Step 1: Clean your teeth to remove any excess plaque and food.Step 2: Unscrew the top of the syringe.Step 3: Apply a quarter of a syringe (1.25ml) to each side of the tray.Step 4: Put the device in your mouth and switch it on to start the 20-minute treatment. (The device will switch off automatically).Step 5: Rinse with water and recharge in either the charging base or attached to the USB charging cord after each use.Step 6: Repeat steps daily for 6 days to complete a full treatment.Expert Advice: When applying the whitening gel to the device, face the shield upwards, so no gel is spilt. You can also use the device alone without the gel to improve overall gum health.