Setting-Up a Twin Cylinder Rig for Expanded Depth or Bottom Time requires the proper Hardware. ZEAGLE's Stainless Steel Twin Cylinder Bands are a necessity for setting up your BC with Twin Cylinders and ZEAGLE offers a set with the ZEAGLE Logo Prominently-Displayed. Bands are Heavy-Gauge for Strength and Durability and are available for 7.25" (18.4cm) diameter or 8" (20.3cm) diameter Cylinders. You'll also need Hardware to Hook-it-Up so don't forget ZEAGLE's Bolt Kit (see SKU: ZGLBK). Bands are covered by a 12 month limited warranty.