1. Remove a piece of plastic underneath the batteries, in battery compartment 2. Brush your teeth before hand 3. Boil some water to 100 degree centigrade and pour the water into a bowl 4. Put the trays in the hot water for just 5 seconds, holding them by the flap 5. Put the trays in your mouth biting to give a perfect mould of your teeth 6. Put the gel in the moulded area of the trays and put them into your mouth 7. Please do not forget to cut the flap from the tray
8. Then switch the LED light and place it on your mouth switching on, Wait for 15-20 minutes.
9. Use the desensitization gel after teeth whitening.