Paughco Custom 820 Gas Tank,4.75 Gallon MUSTNG Narrow Mustang-type features a single-cap, two petcock outlets, straight mounting tabs and a hole-to-hole center line on mounting brackets of 171/2" Extra Wide Mustang-type features a high tunnel for the "Fat bob" look, one left-side petcock outlet and a hole-to-hole center line on mounting brackets of 1711/16" 1-Piece Fat bob style features a left side external petcock outlet, indent on tank bottom for rocker box clearance and a hole-to-hole center line on mounting brackets of 193/4" Dished tank style features a bung for cam-style gas cap, a bung for late-model 22mm petcock and a hole-to-hole center line on mounting brackets of 163/4" Accept 66-72 style vented gas caps (sold separately)