Matters needing attention 1. Do not put it in hot water above 70 degrees and deform it at the same time. 2. At the beginning of use some people will suffer from drooling toothache nausea and other symptoms. This is a normal reaction and can be adjusted for a period of time. 3. Close your mouth naturally when using. Do not chew hard. 4. Do not use dentures or implant dentures. 5. Do not use for serious tooth problems such as severe tooth overlap and flaring. Suitable for children between 6 and 15 years old. Wearing time: 1-2 hours during the day and 8 hours at night. The first stage is soft used to fit the appliance and improve breathing habits and to correct the tooth surface. The second stage is hard and is used for further correction to correct the teeth root and teeth fixed and to act as a retainer.