These tools are complete kits designed to install concrete screws of 1/4 and 3/16 diameter. All you need is the screw and the drill bit. Everything else is included here and presented in a handy blow-molded carrying case with a locking tab to keep it shut. Better yet, the driver in this kit is lobular in design, meaning it grabs the flats of the screw and not the corners. Hence, during installation of painted fasteners, it won't damage the paint.This kit is far better than the ITW Buildex Condrive(R) 500A Tapcon(R) Installation tool for which it is a direct replacement.