These tanks mount in the stock GM battery tray on the passenger side, or any standard battery tray with a GM style hold down. Made specifically for 99-07 GMT800/NBS Trucks and SUVS. May fit other applications with minor work. Has provisions for standard battery mount hardware at the bottom. Can be made with either -10AN, -12AN, or 3/4"NPT bungs. Other configurations available upon request, filler cap and fitting locations can be changed as needed, for custom requests please contact before purchase. PLEASE NOTE FITTING SIZE IN ORDER NOTES BEFORE CHECKOUT!!!!!