... OFF, .for low temperature, .for high temperature.When the warmer is ON, then the LED indicator turns red, at ... switch is off, the heater and the anti-charging function do not work. When fully charged, turn off the ... in a dry place.During use and storage, if the warmer appear abnormal phenomena such as smelly, hot, discoloration, ... on. hot pack pad electric USB li-battery hand warmer CE & ROHS approved