| |  | | Luxfer 19 Cubic Foot Pony Bottle |  | | For a full 19 cubic feet of air, 19 cubic foot pony tanks measure just 20.5 inches by 4.5 inches. This makes for a compact tank with a lot of backup air supply. | |  | | Luxfer 13 Cubic Foot Pony Bottle |  | | 13 cubic foot tanks give you a good backup supply of air in a compact package. The tank measures 4.5 inches in diameter and about 16 inches long. | |