4.1 gallon (15.5 liter). With indented sides and 4.1 gallon capacity. Flush type mounting brackets. Takes 83-up screw type gas caps and 22mm petcock. The separately available recessed and rubber mounted bracket set; with hardware; enables you to flush-mount this gas tank to a custom frame. Dimensions approx.: 56cm long x 31cm wide x 22cm high; 63mm (2 1/2") wide tunnel width. Note: See 516519 flush-mount mounting bracket set for a flush mount to a custom frame. Note: It is advised to pressure test; seal and test fit all tanks before tanks are painted and installed. Some tanks are painted; but this coat is applied for rust prevention during storage only.