Main Steps: 1. Take the plastic circle from battery 2. Fit the mouth tray to the LED light 3. Apply the gel to the mouth tray 4. Place in the mouth, turn on and whiten The led teeth whitening light also work with Gel and the mouth tray. It suggested you can be a kit. Customization: 路 Body color fully customizable 路 Led light color available 路 Led shape designableBulk Teeth Whitening Led website:http://www.teethwhiteningsmile.com/teeth-whitening-led/