CTA Tools 2102 Oil Pump Primer - Ford with 5/16-Inch Hex Drive is designed to prime the lubricating system of new and rebuilt engines. It works by sending oil to the internal moving parts before the first start. The 2102 should be used with a 3/8-inch or 1/2-inch reversible drill. Heavy-duty construction allows for strength and durability. Whether tuning up your ‘68 Corvette or changing the oil on a John Deere tractor, CTA can supply you with the tools needed to do the job. California Prop 65 - Warning, This product contains chemicals known to the State of California to cause cancer, birth defects or other reproductive harm.