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The problems with Fixed Volume Ischial Weight Bearing Sockets have one thing in common. 

Patient feedbacks vary, but essentially they’re all about the same issue. Socket volume.

Ischial discomfort or pain 

- Anterior wall impingement in sitting 

- Request lowering the anterior trim line 

- Request modify ischial containment  

- Complain the socket tore clothes  

- Complain that the socket is too bulky 

- Complain too hot 

Our ActivFIT socket is designed to solve all these frequently experienced issues with socket volume.

Our proven process produces results



CJ Socket-certified prosthetists can order ActivFIT Sails from the factory.

Visit our Training page for details on our half-day course.

You take the ActivFIT Sail measurements from your modified cast or scan.


You send the ActivFIT Sail Order Form to CJ Socket Technologies factory and we’ll turn it around within 24 business hours from receipt of the order.


You fabricate the J-shaped socket and install the finished ActivFIT Sail onto your socket.

Don’t have a lab, or not CJ Socket Certified? Contact us about C-Fab partners or download an order form from one of our CJ Certified Central Fabricators to receive a complete

CJ ActivFIT Socket.


You deliver an ActivFIT user adjustable volume CJ Socket to your patient. Additionally, you can easily adjust the fit using common prosthetic lab equipment.

*CJ Socket-certification is required before you can place an order directly with the factory

Although the CJ Socket is relatively simple, there are pitfalls if done incorrectly.  All prosthetists are encouraged to register for a one day certification course regarding the revolutionary CJ Socket design.  We are committed to your success and will provide training and certification at your facility or online.


If you are not a CJ Socket-certified prosthetist, please view the Training page for course Agenda and additional information.

Order the ActivFIT Socket

At CJ Socket, we understand the importance of providing patients with the best possible prosthetic experience. That's why we've partnered with a network of certified C-Fab locations to make ordering a customized ActivFIT socket as easy as possible. Simply find a C-Fab location near you, place your order, and watch as your patients' mobility and quality of life improves with the next generation of assistive sockets.

Choose a C-Fab partner to order your ActivFIT socket

  • How do I place an ActivFIT CJ Sail order with the factory?
    CJ Socket-certified prosthetists can order ActivFIT CJ Sail from the factory. Email completed order form to: or text picture of completed order form to Toni's cell phone: (845) 987-9271. Don’t have a lab or not CJ Socket Certified? Contact us about C-Fab or scroll up to download an order form from one of our CJ Certified Central Fabricators for your entire socket.​
  • How do I become a CJ Socket-certified prosthetist?
    You need to attend our Introduction to CJ Socket course. This course is a half-day of instruction including a patient fitting. Please contact us via phone (978-922-0413) or email us to schedule.
  • How long will it take to get my ActivFIT CJ Sail?
    Orders are confirmed via phone, email, or text upon receipt. Standard manufacturing to shipping time is 24 business hours from receipt of order. Standard shipping is 2-Day Delivery via the Post Office. However, we also provide Next Day shipping from the Post Office or guaranteed service from UPS. (Some destinations have limited shipping service options.)
  • Does the ActivFIT CJ Sail have a warranty?
    Yes, it’s 90 days from receipt for manufacturer’s defects.
  • Can I use an ActivFIT CJ Sail for any other applications?
    Yes, we have installed CJ Sails on KAFOs and PFFDs.
  • What do you use to make your ActivFIT CJ test sockets?
    The ActivFIT CJ test sockets are made from PETG or ThermoLyn stiff.
  • Do you offer central fabrication for the ActivFIT CJ rigid socket section?
    We do not currently offer central fabrication as a standard service at the CJ Socket factory. However, we have certified 3 central fabricators to produce our ActivFIT CJ Socket. Please visit the Professionals section on the website to download their order forms. If you have a particular manufacturing question or issue, please call (978.922.0413) or email us.
  • The roll at the top of the ActivFIT CJ Sail becomes uncomfortable in sitting. What can be done?
    If the roll at the top of the ActivFIT CJ Sail becomes uncomfortable, you can partially or fully remove the felt roll. Please call (978) 922-0413 for instructions.
  • My patient is complaining of groin pain.
    The ischium should not contact the rigid socket. Make sure your medial wall does to extend posterior to the adductor longus. Check for proper rotation on donning. Make sure the medial wall angles out (medially/ towards the midline) to transition to the Sail’s splay. Your socket may be too deep. Your ML may be too wide.
  • The ActivFIT CJ Sail seems too low below the gluteal fold.
    If the limb is very conical, or the socket requires significant flexion, the ActivFIT CJ Sail can be made with an arc shape to raise up the proximal edge.
  • The patient cannot snug the ActivFIT CJ Sail effectively.
    In cases of poor arm strength, the sail can be made with chaff loops on the batten. This will provide a 2:1 pull and reduce the required strength by 50%. In cases of poor finger strength, sewing large Dacron loops on the closure straps can be helpful.
  • The ActivFIT CJ Socket feels heavy or causes pins and needles (paresthesia)
    The closure may be pulled too tightly. Make sure it is soft in non-weight bearing. In cases of extreme ischemia, the ActivFIT CJ Sail can be left loose while sitting and snugged only when needed to ambulate.
  • The batten on the ActivFIT CJ Sail is pulled over and onto the rigid socket adductor longus area.
    Your socket is out of volume adjustment. Ideally the batten should be between .5 to 1.25 inches posterior to the rigid socket trim line. The Sail should cover half the residual limb and follow a normal shape. Socks and pads may be used to decrease socket volume. Consider a new socket.
  • The 1:1 Velcro closure on the ActivFIT CJ Sail wears out too fast.
    The 1:1 Velcro is under too much tension. Consider a 2:1 Loop attached to batten closure. Consider a 1" pressure buckle + 1" Loop closure and eliminate the Velcro.
  • The ActivFIT CJ Socket rotates externally at heel strike.
    The Scarpa’s modification may be too aggressive. Check for excessive toe out. Use a proximal suspension aid i.e., Coyote, Kiss or a small Velcro strip attached to the gel insert. There are times when with any socket, soft, fleshy or short limbs just need a belt.


Keith Cornell’s new socket design at ‪#‎OPWorldCongress‬ is intriguing. May combine the best of ischial containment and flexible sockets, with fewer of the drawbacks of either.
One of the two new socket designs now being offered for above knee amputees. This design is called the CJ Socket and offers amazing improvements in comfort and adjustability. Set up an appointment today to find out if this is a good option for you. 

Pat Peick, CPO

Thank you for inventing the CJ Socket and making it available to the Prosthetist’s toolbox.  I attended your excellent one day seminar which was one of the best I have ever attended for depth of knowledge and completeness of any new technique.  There will be many amputees across the country who will smile many more times in the day due to the CJ Socket.  I truly liked the seminar and the technique, and you have a naturally educational demeanor.

Joey's story

Meet Joey Z, the amputee. Take two minutes to hear his inspirational story.

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