This oil gauge adapter fitting replaces the tappet screen plug on 1966-1999 Harley-Davidson motorcycles (this fitting is 1/2"-20 thread)

FXRS CONV EM91 LOW RIDER CONVERTIBLE (1991) EM91 LOW RIDER CONVERTIBLE FXRS CONV (1991) LOW RIDER CONVERTIBLE FXRS CONV EM91 (1991)

High quality machined steel locknut with 1 1/2-24 left hand thread fits Harley-Davidson Big Twins 1936-91 4 speed

5 inch centerline radius would measure 5 inches across

Rat Fink Air Valve Caps - Gray Outside Diameter_.563" This oil gauge adapter fittingGrab a pair of mini Rat Finks and be the envy of your friends and neighbors! Great on motorcycles, bicycles, vans, trucks and autos of all type. Rat Fink is 1 1 8" tall. Made to fit most standard valve stems. Sold in Pairs.