Specifications: Made of food grade silicone material, safe to use. Two teeth trays: one for upper teeth and one for lower teeth. Very suitable for preventing teeth grinding at night and whitening teeth. Usage Instructions: 1. Place the tray into hot water about 70 degree celsius for 10-15s to soften and then remove it from the water. 2. Place the trays into your mouth and press the bonding surface of tray and gum. The tray is now moulded. 3. Cut off the extra gum line and finish the tray making. Type: Teeth Whitening Tray Material: Food Grade Silicone Quantity: 2Pcs Size: 6.5cm x 6cm x 1.3cm/2.56" x 2.36" x 0.51" (Approx.) Notes: If the tray is not made well, you can repeat the process for the second mould. Please clean the tray with water before using. The replacement time of the trays is 3-4 months. It is normal to feel discomfort for the first time to wear the tray. You will get used to it after several times. Due to the light and screen setting difference, the items color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 2 x Teeth Whitening Tray No matter what time, day or night, our guards are your perfect solution. Mouth guards are long-lasting, soft, comfortable and safe material. Sleep mouth guard are completely form fitting, durable in strong for total mouth protection. Easy to clean for repeated use Two teeth trays: one for upper teeth and one for lower teeth. It can adapt to various tooth arrangement, tooth size and mouth shape to obtain the best comfort. Very suitable for preventing teeth grinding at night and whitening teeth.