Overview USAGE: Step 1: Clean the tooth surface Step 2: Apply gums. Light curing 2min The third step: smear whitening agent, cold light for 8 minutes. Step 4: remove the whitening agent and then coated with a new layer of whitening agent, cold light for 8 minutes. Step 5: Repeat the fourth step, a total of cold light irradiation 3 times (8 minutes each time). Step 6: remove the treatment items, warm water mouthwash. Note Due to the different monitor and light effects, the actual color of the item might be slightly different from the color showed in the pictures. Thank you! Please allow 1-3cm measuring deviation due to manual measurement.