The Pro-Lite 5.5 Super Comp Leash is designed for small wave surf with a thickness of 5mm. It is made of super lightweight extra tough urethane, a stainless steel double swivel and a finished neoprene ankle cuff for maximum comfort. The custom pro-lite mold with super flexible ends backed by the recessed horn virtually eliminates pull. Did I forget to mention the detachable rail saver and key pocket, as if you weren't already adding this to your wish list.