The Rapid Diver tank holster, constructed from reinforced 1050 denier ballistic nylon, is capable of holding an additional 20cu ft SCUBA cylinder up to a full sized SCUBA cylinder which allows the Rapid Diver to be used as a back mounted tank system. A padded back support insert is included which can be removed to add in a Camelbaktm type hydration system or similar hydration system if desired. This pad is standard on all Rapid Diver Systems and is mounted on the back of the Rapid Diver vest by two 2” buckles. It is an integral part of the fit of the system as it connects the split saddle strap and waist band to the front of the Rapid Diver vest.