The cordless wrench is an power wrench with lithium-ion battery and can be recharged repeatedly. It is a tool for tightening high-strength bolts. When working, align the wrench head with the bolt head, and turn the switch to start working. After working, pull out the wrench and pull the trigger to pop out the ring head. Mainly used in steel structure installation industry.This kind of electric wrench does not need external power supply when it works, so it is very suitable for use in the field or where there is no power supply.