Used Scubapro Alpha Boot 4mmThe Alpha boot introduces an innovative approach to dive boot design that addresses the needs of both temperate and cold water divers. The Alpha boot employs a laced closure instead of a zipper on the body of the boot. The laced closure enables you to achieve a snug, comfortable fit, and then tops it off with a Velcro strap on the ankle for maximum security. The unique two layer construction combines neoprene and nylon along with anti abrasion fabric