ST&G makes Ridgeflex Ankle Joint, which uses a unique material called Prepalon. This material uses Continuous Fiber Elastomer Technology (CFET), which balances stiffness and flexibility well. CFET allows for a tendon design that enables smooth movement, proper support, and control over rotation. By blending continuous fiber into the elastomer, the joint stays rigid without stretching, eliminating the need for additional materials like string. The flexible elastomer increases tear strength, while the blended fiber adds support.