The backplate, a plate, generally made from chrome steel, in some cases aluminium or carbon fibre composite, which happens to be held in opposition to the diver's again from the harness, and to which the diver's Major cylinder or cylinders are attached. An underwater scooter works precisely the same way https://bbs.pku.edu.cn/v2/jump-to.php?url=https://asiwoturkiye.com