4.75 gallon (18 liter). Dual cap. Takes pre-83 bajonet style vented gas cap and 22mm 75-up style petcock. Approx. dimensions: Tank length 19?”; tank width 13″; tank depth 8″; tunnel length 19?” ; tunnel depth 4?”; tunnel width 2-3/16″; hole to hole on mount bracket 19_”. 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.