rechargeable explosion proof hand warmer electric hot water bag

1. Long warming. Take 8-15 minutes to heat up only, which can keep warming hand for 3 hours and warming quilt for 8 hours. 
2. Automatic power-off .When temperature reaches 70 degree, the power will cut automatically to prevent to heating.
3. Explosion proof. In case of the thermostat broken, the other expansion controller will begin to operate. When the temperature is up to 90 degrees, the expansion controller star to expand and break both electrodes so as to shut off the power supply.
4. Quality is reliable. The electric hot water bottle/Hand warmer is made of ultra- strong rubber film composite fiber. The heating medium is used to heat up the heating element and reserve the energy.
5. Simple style.