Frequently Asked Questions
What is the ProHensor, and how is it different from other prosthetic hooks or devices?
Traditional prosthetic hooks often require users to choose between direct grip control and the ability to maintain a hold without continuous effort. Marins developed the ProHensor® family to deliver greater control, versatility, and functional capability in body-powered prosthetics.
The ProHensor® VC is a heavy-duty voluntary-closing terminal device with a lyre shape that gives users direct, proportional control over grasp force. Unlike conventional single-width hooks, it offers two selectable grip widths for both precision handling and larger objects. Its durable construction, replaceable fingers, and grip plates provide versatility and simplify maintenance without requiring replacement of the entire device.
The ProHensor® VCAL™ takes body-powered functionality further with integrated automatic locking. Its patented LockCore™ mechanism engages during closing and maintains a dynamic locked grasp without continuous cable tension. Unlike a traditional manual cable lock, the locking mechanism operates automatically within the terminal device. This allows users to maintain a secure hold while lifting, carrying, repositioning, or working in positions where maintaining cable tension can be difficult. The result is greater freedom of movement, reduced sustained effort, and more functional control during demanding activities.
With three operating modes, including a non-locking option for repetitive tasks, the VCAL combines precise voluntary-closing control with secure sustained grasp.
Both devices are fully mechanical, require no batteries or electronics, and feature replaceable components designed for long-term serviceability.
How does the VCAL's automatic locking work?
The ProHensor VCAL automatically engages its LockCore™ mechanism during closing. The mechanism can lock at any point along the closing path, allowing the user to establish the desired grasp before releasing cable tension.
The device then maintains a dynamic locked grasp without requiring continuous effort to keep the fingers closed.
To release the object, the user applies a brief cable pull and releases it. The fingers return to the fully open position, resetting the mechanism for the next grasp.
Can I choose different grip modes?
Yes. Both devices offer selectable grip configurations.
The ProHensor VC has two modes:
- Wide voluntary-closing grip
- Narrow voluntary-closing grip
The ProHensor VCAL has three modes:
- Wide grip with automatic locking
- Narrow grip with automatic locking
- Narrow grip without locking
The non-locking VCAL mode is useful for tasks that involve repeated grasping and releasing. Your prosthetist can demonstrate how to select and use each mode.
Is the ProHensor easy to use?
The ProHensor® is designed to feel familiar to users who already use a body-powered prosthesis. It uses direct body-powered control, so the user can feel and manage grip through movement and cable tension.
The ProHensor® VCAL™ may require some additional practice because it includes a locking function. Once fitted and adjusted properly by a prosthetist, users can learn when to use the locking hold and when to use standard voluntary-closing control.
Is it covered by insurance?
Coverage depends on your insurance plan, your clinical documentation, and the medical necessity determined by your prosthetist and care team.
The ProHensor® and ProHensor® VCAL™ are prosthetic terminal devices, and your prosthetist can help determine the appropriate documentation and reimbursement pathway. Marins can provide product information to support your prosthetist or clinic, but insurance approval is not guaranteed.
Can I switch between the ProHensor and my current prosthetic?
In many cases, yes. Both the ProHensor VC and VCAL are designed to connect to standard body-powered prosthetic systems.
Compatibility depends on your existing socket, wrist unit, harness, cable setup, and overall prosthetic configuration.
Your prosthetist can determine whether either device is compatible with your current system or whether adjustments are needed.
Will I need to see a prosthetist to use the ProHensor
Yes. A prosthetist should evaluate, fit, and adjust the ProHensor® or ProHensor® VCAL™ as part of your prosthetic system.
Proper setup matters. Cable tension, harness fit, wrist compatibility, and user training all affect how the device performs. For the ProHensor® VCAL™, your prosthetist can also help you learn how to use the locking function safely and effectively.
Is it a good option if I've never used a prosthetic before?
It may be, but that decision should be made with a prosthetist. The ProHensor® may be appropriate for some new body-powered users because it offers direct control and strong functional grasp.
The ProHensor® VCAL™ may also be considered for new users, especially when secure holding is an important goal, but it includes an added locking function that requires instruction and practice. Your prosthetist can help determine which option best fits your goals, strength, daily activities, and training needs.
How is it different from a myoelectric hand?
A myoelectric hand uses sensors, batteries, motors, and electronics to open and close. The ProHensor® and ProHensor® VCAL™ are body-powered, meaning they are operated through the user’s own body movement, harness, and cable system.
Body-powered devices are often valued for durability, direct control, feedback through the cable system, and use in active or demanding environments. The ProHensor® VCAL™ is different because it combines body-powered voluntary-closing control with an integrated locking hold, without relying on electronics or batteries.
How do I get one?
Start by speaking with your prosthetist or contacting Marins.
ProHensor devices are supplied through prosthetic clinics and professional distribution channels rather than sold directly to individual users.
Your prosthetist can evaluate which device is appropriate, confirm compatibility with your prosthetic system, and arrange ordering and fitting.
Marins can provide product information, educational resources, and assistance connecting your clinic with the appropriate purchasing channel.
Can I use it for tough jobs—yardwork, construction, dirty environments?
The ProHensor VC and VCAL were designed with active users in mind, including people who build, repair, lift, carry, and work in demanding environments.
The VCAL may be particularly beneficial for tasks requiring a sustained hold, such as carrying materials, stabilizing tools, or working with both arms.
Both devices require appropriate cleaning and maintenance. Exposure to water, dirt, sand, and other debris should be managed according to Marins' care instructions. Neither device should be treated as waterproof.
Your prosthetist should help evaluate the device's suitability for your specific activities and working conditions.
What if it breaks? How long does it last?
Both devices are designed for durability and serviceability. Their useful life depends on activity level, operating conditions, and maintenance.
The ProHensor VC and VCAL have replaceable fingers and grip plates. The VCAL also includes a clinic-serviceable LockCore™ mechanism, allowing certain repairs without replacing the complete device.
The ProHensor VC includes a 24-month limited warranty. The VCAL includes a 12-month limited warranty, with 24-month structural coverage for the outer housing.
Both warranties begin when the device is fitted to the patient. Normal wear is not covered, but qualifying defects in materials or workmanship are covered under the applicable terms.
Contact your prosthetist or Marins if service is needed.
Where can I find instructions, demonstrations, and additional information?
Marins provides operating instructions, videos, and educational resources to help users understand both devices.
You can watch demonstrations of the VCAL's three modes, automatic locking and release, and use during everyday activities.
Your prosthetist can also explain fitting, maintenance, and safe operation.
Visit MarinsMed.com or explore our Directions for Use and Resources.
What are the clinical indications for the ProHensor VCAL?
The ProHensor VC is a heavy-duty voluntary-closing terminal device intended for patients who benefit from direct, graded grasp-force control, selectable grip widths, and durable, serviceable construction.
The ProHensor VCAL may be particularly appropriate for patients whose activities require sustained grasp without continuous cable tension. Relevant activities include carrying, lifting, tool use, object stabilization, bimanual tasks, and work across varied positions.
The VCAL combines user-controlled grasp-force generation with automatic grasp retention, allowing the patient to maintain a hold after releasing cable tension.
Selection should reflect the patient's activity profile, functional demands, strength, prosthetic configuration, and clinical evaluation.
How does the ProHensor differ from a standard Hosmer hook?
Traditional voluntary-opening hooks generally use spring or elastic tension to maintain closure while cable input opens the fingers.
The ProHensor VC and VCAL use voluntary-closing control, allowing the user to establish and regulate grasp force through cable tension.
The ProHensor VC provides this control with two selectable grip widths and replaceable fingers.
The ProHensor VCAL adds integrated automatic locking. Once the user establishes the desired grasp, the device maintains the hold without continuous cable tension.
Unlike a conventional manual cable-position lock, VCAL's internal LockCore™ mechanism engages automatically during closing and supports dynamic locked grasp.
Is it compatible with standard components and harness systems?
Yes. The ProHensor® and ProHensor® VCAL™ are designed to work with standard body-powered upper-limb prosthetic systems, including common harness and cable setups.
Compatibility should be confirmed by the prosthetist based on the patient’s existing socket, wrist unit, cable routing, harness configuration, and functional needs. Proper setup, alignment, and cable tension are important for optimal performance.
What configurations and specifications should clinicians know when selecting a device?
Both the ProHensor VC and VCAL feature:
- Wide grip with a maximum opening of 3 inches (7.6 cm)
- Narrow grip with a maximum opening of 1.25 inches (3.2 cm)
- Standard 1/2-20 wrist connection
- Left- or right-side configuration during fitting
- Replaceable finger assemblies and grip plates
The ProHensor VC provides two non-locking voluntary-closing grip modes.
The VCAL provides wide and narrow automatic-locking modes plus a narrow non-locking mode for repetitive grasp and release.
Clinicians should confirm compatibility and review the applicable product specifications and Directions for Use before fitting.
How does VCAL's automatic locking differ from a manual cable lock?
A conventional manual cable lock secures the cable at a selected position. The user typically must engage and release the lock separately.
The ProHensor VCAL uses an integrated LockCore™ mechanism within the terminal device. Locking engages automatically during the closing sequence, after the user establishes the desired grasp.
Rather than simply fixing the cable position, the mechanism maintains a dynamic locked grasp that provides continued resistance to opening forces after cable tension is released.
This distinction may be clinically important during sustained grasp, loaded activities, and tasks requiring changes in working position.
How do I order for a patient?
ProHensor devices are available through Marins and participating professional distributors.
Clinics may order through their established distributor or contact Marins for current purchasing options.
When ordering, identify the requested device, ProHensor VC or ProHensor VCAL, and confirm any required product configuration and supporting documentation.
Orders are processed according to the purchasing channel's procedures, which may include purchase orders, institutional purchasing systems, or direct invoicing where available.
Contact Marins for assistance with product selection, specifications, ordering, or distributor information.
How can I obtain current pricing, availability, and shipping information?
Pricing and fulfillment information are available through Marins or the distributor handling the order.
Some distributors maintain inventory, while other orders may be fulfilled directly by Marins or through an agreed drop-shipment arrangement.
Clinics should confirm current pricing, stock availability, order cutoff times, estimated shipping dates, and delivery arrangements with their purchasing channel when ordering.
Special shipping requests or expedited fulfillment should be confirmed in advance.
What warranty coverage is provided, and when does it begin?
Marins provides limited warranties for both terminal devices.
ProHensor VC
- 24-month limited warranty for qualifying defects and covered functional malfunctions
- Replaceable fingers and external components covered for qualifying defects, excluding normal wear
ProHensor VCAL
- 12-month limited warranty covering the device, including LockCore™ and fingers, for qualifying defects and covered functional malfunctions
- Additional 24-month coverage for structural defects in the outer housing
- Normal wear excluded
Both warranties begin on the date the device is fitted to the patient, rather than the purchase or shipment date.
Authorized component replacement and service performed according to Marins' instructions do not void the applicable warranty.
Complete warranty terms, limitations, and exclusions are available from Marins.
What is the return policy, and how are defective products handled?
Return procedures depend on the reason for return and the original purchasing channel.
For warranty concerns, the professional customer should contact Marins or the appropriate distributor to initiate evaluation and obtain return authorization when required.
Warranty claims must be initiated within 30 days of discovering the reported defect or malfunction. Marins may request the affected device or component for inspection.
Are product demonstrations or patient trial devices available?
Clinicians may contact Marins to request a product demonstration or discuss opportunities for clinical evaluation.
Can it be serviced in-clinic?
Yes. Both ProHensor devices are designed with replaceable components.
Finger assemblies and grip plates can be replaced in the clinic by qualified professionals following Marins' service instructions.
The ProHensor VCAL also incorporates the replaceable LockCore™ locking mechanism, allowing approved maintenance or replacement without replacing the complete terminal device.
Service should be performed by trained professionals using Marins' instructions and approved components.
The ProHensor VC and VCAL are separate devices. The non-locking ProHensor VC cannot be converted to a VCAL by installing a LockCore.
What training and resources are available?
Marins provides clinical and educational resources for device evaluation, fitting, operation, service, and reimbursement documentation.
Available resources include:
- VCAL in Practice: A free clinical demonstration of voluntary-closing control, automatic locking, and functional applications
- Clinical Guides: Device specifications, clinical considerations, and coding information
- Directions for Use: Operating instructions and demonstrations
- Service Videos: Finger installation and LockCore replacement
- Letter of Medical Necessity Assistant: A resource for developing patient-specific supporting documentation
- Functional Evaluation Materials: Clinical observations and task-based testing information
Visit the CE Courses, Directions for Use, and Letter of Medical Necessity Assistant pages.
What HCPCS codes apply?
Marins recommends consideration of the following HCPCS codes.
ProHensor VC: L6722
Terminal device, hook or hand, heavy duty, mechanical, voluntary closing, any material, any size, lined or unlined.
ProHensor VCAL: L7499
Upper-extremity prosthesis, not otherwise specified.
The VCAL's integrated automatic-locking function is not specifically described by the standard voluntary-closing terminal-device code.
Marins provides product descriptions, specifications, clinical resources, and supporting documentation to assist with reimbursement submissions.
Suggested codes do not constitute a payer determination or guarantee reimbursement. Final coding, coverage, and payment decisions depend on the applicable payer, professional judgment, and patient-specific documentation.
Can patients purchase directly?
No. Marins supplies ProHensor devices through prosthetic clinics and professional distribution channels.
A qualified prosthetist should evaluate device selection, confirm compatibility, and complete the required fitting, adjustments, and patient instruction.
Patients may contact Marins directly for product information or assistance connecting their clinic with the appropriate purchasing channel.
Who should clinics contact for product support, service, or ordering assistance?
Marins provides support for product specifications, device operation, service inquiries, warranty claims, clinical resources, and purchasing questions.
Marins, Inc.
Georgetown, Delaware
Email: Admin@MarinsMed.com
Phone: 424-262-7467
Website: MarinsMed.com
For orders placed through a distributor, clinics should also follow that distributor's established customer service and purchasing procedures.
What sets Marins apart?
Marins develops mechanical upper-limb prosthetic technology focused on functional performance, direct user control, durability, and serviceability.
The company was co-founded by Darryl DuBre, an upper-limb amputee, inventor, and body-powered prosthesis user since 1990. His personal experience has played a central role in developing the ProHensor devices.
Marins' ProHensor VC provides heavy-duty voluntary-closing control with selectable grip widths and replaceable components.
The ProHensor VCAL introduces integrated automatic locking, allowing users to establish grasp force and maintain a dynamic locked hold without continuous cable tension.
Together, these technologies expand the functional choices available within body-powered upper-limb prosthetics.
Still have questions?
Contact Admin@MarinsMed.com or visit our Resources page.