ZamstA(R) ZK-X :: Extra Strong support sleeve knee support with semi-open design for superior fit and slipping prevention. Crisscrossed and parallel straps provide effective compression and intense anterior stability for lower leg. External medial and lateral metal hinges improve lateral/medial stability enabling smooth flexion and extension. Adjustment straps on top/front and lower/rear help lock brace in place. Preventative and/or supportive of activity after moderate or severe sprain. Ideal for ACL MCL and LCL support.