Features: 1.Portable hanging neck design, which is different from traditional hand warmers, freeing hands; 2.It is ergonomic and heats evenly in a large area 3.Four levels of temperature, press buttons to adjust, whatever you want. has intelligent temperature control and will not cause excessive temperature to harm human skin. 4.Quadruple safety protection of heating plate: current protection + temperature control protection + charging protection + over-discharge protection. 5.100%brands newif you have any questionsplease contact us Notice: Please allow 1-3cm deviation due to manual measurement Actual color may be slightly different from the image due to different monitor and light effect Description Rated power: 5W Input voltage: 5V-1A Rated frequency: 50Hz Product size: 4.5*4.5*1.5cm Control method: mechanical button Battery capacity: 600mAH includes: 1X Neck Warmer Set