How to use:
1. Pull the locking button down and hold it firmly. The wrench is unlocked.
2. Turn the handle to adjust the torque while holding down the locking button.
3. Turn clockwise to increase torque, and counter-clockwise to reduce torque.
4. After adjusting the required torque, release the hand and the button jumps back and locks the handle.
5. Turn the handle left and right to ensure the wrench is locked and start using.