CTA Tools 2101 Oil Pump Primer , GM Primes the Lubricating System of New and Rebuilt Engines Sends Oil to the Internal Moving Parts Before the First Start Used with a 3/8-Inch or 1/2-Inch Reversible Drill Heavy-Duty Construction Allows for Strength and Durability CTA Tools Offers One of the Widest Ranges of Professional Specialty Tools in the Market