Sale is for a vintage new Oil Pump Driving Gear and Shaft, as pictured.  Original packaging missing.  

Approximate dimensions:  Length overall 8.88"; Shaft diameter 0.54"; Gear diameter 1.65"; Gear Height 1.26"; Gear teeth 14.  

Tentatively identified as GM # 1305540, or equivalent replacement, to fit:
1936 - 1939     Buick series 60,80,90
1940                Buick series 60,70,80,90
1941 - 1942     Buick series 60,70,90
1946 - 1952     Buick series 70

Verify suitable for intended use as returns are not accepted.