The Wheeler Engineering F.A.T. Wrench is a hand driven, click/clutch system torque wrench that is very useful in applying the necessary torque to most firearms and firearm accessory fasteners. Common uses include, but are not limited to, instillation of scope rings and base screws, action screws and trigger guard screws. The F.A.T. wrench is used like a screwdriver; it is not a ratcheting device. It features an ergonomic handle and a standard 1/4 in. hex drive tip that can be used to apply torque from 10 in./lbs. to 65 in./lbs. at 5 in./lbs. increments. Accuracy is +/- 2 in./lbs. up to 40 in./lbs., 40 to 65 is +/- 5%. Bits are made of S2 tool steel and hardened to 56-58 Rockwell C. The set Includes: (10) bits (hex to square adapter, #10 flat blade, #32 flat blade, #11 flat blade, 5/32 hex, 7/64 hex, 3/32 hex, T20 Torx, T15 Torx and Leupold spec). Adjusting the F.A.T. wrench beyond the torque wrench setting of 65 in./lbs. may damage the internal mechanisms, resulting in inaccurate torque adjustments. Leaving the F.A.T. wrench adjusted at a high torque setting for extended periods of time may damage the internal mechanisms, resulting in inaccurate torque adjustments. Always adjust the F.A.T. wrench to the lowest torque setting after each use. This product is covered by a limited lifetime warranty provided by Wheeler. Made by Wheeler™ Tools.