Correct three piece extendable antenna mast with round ball tip. Includes rubber grommet at base. Mast press fits into the antenna base on cars factory equipped with a manual antenna. Mast only, bases are unavailable at this time. Shaft length below washer is 3 1/2", and 5/16" in diameter. 1961-65 Buick Skylark and GS models 1952-62 Oldsmobile 88, 98, Starfire and Fiesta with manual antenna 1961-66 Oldsmobile F-85, Cutlass and 442