A) Heat a pot of water to 80-90C (do not boil, then the tray will melt B) Hold the handle and dip the tray nozzle in water for about 5-10 seconds. Be careful, as overexposure will melt/shrink the tile, but underexposure will make formation more difficult. C) Remove the tile from the water and hold to drain excess water for one second. D) When the tray becomes soft, place the tray in your mouth and mold it around your teeth. Use your fingers to press down on the inside and outside of the teeth. Hold the tray firmly in your mouth at the same time. E) Remove the tray. Repeat this process for the bottom tray. Cut off the handle and trim the shaped tray, cutting at the gum line. This will allow you to clean any gel that may have leaked onto your gums. F) Simply apply teeth whitening or remineralizing gel and place the tray Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-DIMEANI official store