Check the listing for details. Orthodontic Comfort Stability Dental Teeth Alignment Trainer for Alignment T4A. Condition: New. Listed at 8.95 USD. T4A For Alignment Hardness:SoftPacking:1pc/BoxSuit for: 8-15 year oldWearing time: 1-2 hours during the day and 8 hours at night. Matters needing attention1. 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.