3 Button setting: unit button, power button, tare button. Power button for switching on/off and locking functions. Tare button for removing tare and choosing locking functions. Unit button for changing weight unit from kg>lb. >jin>oz. >kg>lb. Auto power off save energy: not used in 120 seconds, will turn off automatically. High quality 50kg/5g digital hanging scale, portable and easy for use.