ZEAGLE's Twin Cylinder Mounting Plates are an Alternative to a Full Metal Back-Plate when Mounting Twin Cylinders to your ZEAGLE BC. The Plates are mounted in the same location as a Metal Back-Plate. Mounting Plates Distribute the Weight of the Cylinders so as not to Damage-or-Stress the Material of the BC Vest while on the surface. Use of the Plates requires a Set of Twin Cylinders equipped with ZEAGLE Stainless Steel Twin Cylinder Bands (see SKU: GLTB) and ZEAGLE Bolt Kit (see SKU: ZGLBK). Plates Sold as Pair and Bands give 8 5/8" (23cm) Tank Centers. Mounting Plates are made from Stainless Steel and are covered by a 12 month limited warranty.