the HMS KO1655 is a knee brace or stabilizer. Its purpose is to prevent the knee from moving sideways and backwards during recovery from a sprain or other injury. The brace is also used as an injury prevention device. the HMS KO1655 brace is made of a combination of neoprene, polyester and nylon in an airprene finish. The resulting material is elastic, stretchable in all directions, and the Velcro system allows you to adjust the stabilizer to your exact needs. Reinforcements are sewn into the sides to prevent the knee from moving sideways and backwards. There is a zippered pocket in the front with a silicone ring to stabilize the kneecap. The ring can be easily removed and it is up to you how much you need to stabilize the knee.