Ossur's Trainer OTS is the ideal support for MCL injuries. The Trainer has a carbon range-of-motion hinge and carbon shell making it extremely durable, yet also capable of being used in sports where medial hinges are restricted or interfere with performance. The Trainer OTS comes in 5 sizes: XS, S, M, L, & XL. To find your size measure the diameter around your leg 6" above the patella and consult the Specifications Tab.