Neoprene Support knee open small size (cm) thickness 31.5- 36.5 3 mm, Neoprene open knee support -small 31.5-40.0 cm , Protection, Warmth, Performance, Support, Rehabilitation, Top quality sports grade supports made in 3mm neoprene for maximum performance and durability. Ideal for sport activities and everyday use. Closed cell neoprene rubber provides warmth and support to encourage recovery and to help prevent injury to joints and muscles. Blood circulation is improved which assists the natural healing process.