Designed with polyurethane foam for maximum shock absorption. Absorbs impact to help prevent injury and protects against bruises and friction burns.   Measure the circumference of the knee at the patella with knee fully extended. SIZE : UNIVERSAL , UNIT : 1 PAIR, Washing Instruction Hand wash in cold water with mild soap. Rinse thoroughly. Air dry at room temperature. Do not machine wash or dry. Should a rash or irritation occur, discontinue use and consult your physician.