Specification: Suitable For: Phase I and Phase IIandPhase III Type: Teeth Tray Color: Transparent/Blue Material: Silicone How to distinguish the three stages: by the number on the package Transparent stage 1-YG21905-2/ Transparent stage 2-YG21905-4/ Transparent stage 3-YG21905-6 Blue stage 1-YG21905-1/Blue stage 2-YG21905-3/Blue Stage 3-YG21905-5 Package Contents: 1 x Teeth Retainer or 1 set(3pcs)Teeth Retainer Function: (It is recommended to buy in three stages (D1 D2 D3), When used in this way, the effect will be faster and more obvious ) Phase 1: correcting the tooth surface Hardness: soft Service life: 1-2 months Function: Used to accommodate orthotics and primary orthotics Phase 2: root correction Hardness: Moderate Service life: 2-3 months Function: to further adapt to orthotics and enhance the correction effect Phase 3: consolidation and shaping Hardness: Hard Service life: 3-6 months Function: Increase correction strength for later shaping. Features: Made of food grade silicone material, which is non-toxic, oddless, healthy and safe. No color change, it will maintain the original color and not turn to yellow, whenever how long you use it. Groove design can fit the surface of the teeth well to allow for normal breathing and protection of your teeth during exercise. It can reach to rear molars, to provide complete protection.Invisible color, you can witness tooth change process. It can improve facial shape to promote the normal development of jaw. Can be used as a late addition maintaining for some tooth problems. Instructions for use: 1. At the initial stage of wearing, the wearing time should not be too long. It can be gradually increased and gradually adjusted. 2. If you feel discomfort or pain in your teeth, take it down, have a rest, and then wear it again. 3. Don't bite your teeth hard at first. After adaptation, the occlusal force can be increased. 4. Wear it for 1-2 hours during the day after adaptation. After the teeth get used to the braces, the use time can be increased. 5.Tooth orthodontic is a long process, please be patient for the effect. Do not suspect their effect, they need time to proof themself