Features: Brand new and high quality. Anyone can use it because it has a unique size and can be molded in warm water. Put the trayin 70 degrees warm water for 10-15 seconds to make the traysoft. Do not use 90 degree hot water that is too hot. Then remove it from the hot water. Place the tray on the tooth to make an impreion. Trim the formed tray and cut at the gum line. It is very suitable for teeth whitening. Replace it every 3-4 months, you may feel uncomfortable at first, and you will get used to it after a few times.Specification:Material: Thermoplastic Copolymer Size: 7*7*1.5cm Color: Transparent Quantity: 2/4pcs Note: There could be some slight differences in the color tone of the pictures and the actual item. Please allow 1-2mm differs due to manual measurement, thanks.Package Included:1/2 Pair xTooth TrayNo Retail Box. Packing Safely in Bubble Bag.