SBC/BBC oil pump primer tool. Simple to use drop on the distributor hole of the engine hook the drill up to the three sided primer driveshaft (no slipping in the drill chuck) pull the drill trigger and spin away until you get oil pressure and precious engine blood up to the rocker arms. Tool will last for years and lots and lots of engine builds. Tool is made with a heat treated steel shaft that is black oxide coated with billet alum. anodized bushings that center the primer tool on the engine block. Works with all large flat tang oil pump drives.