Stainless Steel Buckle Adds Strength for the Heaviest Batteries. T-H Marine's Battery Holder tray holds two 31 series deep cycle batteries in the tightest of spaces.• Capacity: Single• Used With: Group 31 Battery• Finish: Matte• Color: Black• Material: Plastic (Polypropylene)• Includes Mounting Hardware: Yes• Drilling Required: No Meets All NMMA Specifications Easy To Install | T-H Marine Supplies Battery Tray, For Use With 31 Series Battery