Colony duplicates or custom style oil filler caps with dipstick, come complete with gasket or o-ring. Available for 1936 thru 1940 E & EL, 1938 thru 1947 U, UL, UH & ULH and 1941 thru 1964 F & FL Big Twins. Also suitable for other oil tanks with 1 1/4"-12 thread.