Billet Aluminum Optima Battery Tray (Group 75/35 , 75/25)- Polished Machined from 5/16 inches thick 6061-T6 aluminum and polished. Stainless Steel ASSEMBLY hardware included. Each standoff is machined from 1/2 inches diameter aluminum tubing. Accommodates (4) post GROUP 75/35 and 75/25 Yellow, Red and Blue Top Optima Batteries as well as any battery that fits within the listed dimensions. Dimensions of pocket that houses battery:Length = 10 inches Width = 6 13/16 inches Height = 6 3/4 inches