Having the Proper-Hardware as Spares, or if you're setting up a Back Plate and you use 7.25" (18.4cm) Diameter-Cylinders this Kit is what you are looking for. Kit comes with all the Hardware you need to Properly-Set-Up your Back-Plate for Diving. The Stainless Steel Bolts and Fasteners guarantee's Corrosion Resistance and Secure Cylinder Mounting. Kit Includes 2 Stainless Steel Bolts, Washers, Nuts and Butterfly Fasteners. Kit is covered by a 12 month limited warranty.