40 piece set covers taps and dies from No. 4 to 1/2". Ratcheting "T" Wrench provides a 5 degree ratcheting arc for tapping engine blocks. Replaces need for slower existing tap and die wrenches. Reversible lever allows quick change from forward to reverse eliminates hand over hand turning. Twist Lock Guide System keeps dies centered while cutting threads GearWrench Tap and Die Set includes Index holders for taps. All taps and dies lock in place. Features comfort shaped grips.