Features: 1. Contains 2 button batteries. Note that there is an insulating sheet in the middle of the battery. Take it out before use. 2. Uses: need to be used with gel Irradiation by a single lamp has no effect. 3. Fast and Convenient. Simple To Use.Easy to maintain. Convenient to carry 4. Teeth Whitening Light support sustainable work for 48 hours. 5. Whitens in just 10 minutes. Removes tooth stains, and provides long lasting results. Fast and easy to use, it can be used conveniently at home. Notice: 1. Actual color may be slightly different from the image due to different monitor and light effect. Please allow 1-3cm deviation due to manual measurement. Specification: Power supply: 2 button batteries included Rated voltage: 6V Blue wavelength: 460 470nM Function: whitening Voltage: DC6V LED lights: 1 star Blue light intensity: 400-600 mcs Blue wavelength: 460-465 nm Product color: blue Light color:blue Package List: 1 x Teeth Whitening Light with button battery