Although the UTX Stable FS is very similar to Stable 80 and 120, its cored is low weight, strong and, placed medially. This aids the orthosis in controlling an unstable valgus knee. The UTX Stable FS is like standard bracing systems as it is locked in two positions, walking and standing. The planta flexion ankle joint is controlled by a spring and causes ankle movement to be smoother and natural. It has fixed equinus and a caliper that is non-weight bearing. Unlocking the device is easy and can be done by simply pulling the knob found at the top. In fact, it is easier to unlock the UTX Stable FS than other conventional calipers. Also, the simplicity of unlocking it allows the person to safely sit. The device weighs 900 grams and can accommodate up to 100 kg of body weight.