Wheeler's 89-Piece Screwdriver Set has proven itself an asset to any gunsmithing workbench with its premium bits that reduce burred and busted screws. The bits have a Rockwell hardness rating of 56-58 to handle heavy torque. The 54 hollow-ground bits range in size from .120"x.020" to .360"x.070". Doubles are included in the thinnest sizes. 15 specialty bits aid in the installation of scope bases and other specialty tasks. Set also includes a complete assortment of Phillips, Allen and Torx bits. Set comes with two driver handles – one regular size for general gunsmithing tasks and one compact for confined spaces and finesse work with smaller bits. Set also includes a Wheeler Level-Level-Level™ that mounts to the receiver rather than the top of the scope base to ensure perfectly level crosshairs.