The 6Н30B hydraulic knee joint is recommended for patients weighing more than 125 kg with unilateral or bilateral transfemoral amputation at any level, including knee joint amputation. 6H30B hydraulic knee joint is water resistant. The hydraulic knee joint is a single-center knee with a rotary hydraulic system that controls. It has a mechanical lock in the developed position for patient safety which B is suitable for use in aquatic environments.