Made of 75% Rubber foam and 25% Nylon; * Comfortable, extend, light; * Provide enough support for your shin and calf; * Improve blood circulation, accelerate rehabilitation. * Four avaiable size:S(12.9~13.9 inch),M(13.9~14.9 inch),L(14.9~16.9 inch);XL(16.9~17.9 inch).