Torque wrenches come in two varieties: click type, and direct reading. The click type torque wrenches are used mostly for tightening. When the set torque is achieved a “Click!” sound indicates tightened to completion. The direct reading torque wrenches are used mostly for measuring and inspection. They display measurement values. The Pokayoke (error-proofing) torque wrenches help prevent human tightening errors. They come in three varieties: wired, wireless and marking.