Originally, there were two, but I used one, so I'm selling only the other one. [Lightweight & Thin] Teeth Grinding Mouthguard (Molding Type) Night Guard [Set Contents] Teeth grinding mouthguard x 1, dedicated case x 1, Japanese instruction manual [Materials] Main body material: EVA resin, Case material: PP resin [Size] Free size (can be customized by cutting with scissors) ■Recommended for those who: Are concerned about teeth grinding, clenching, temporomandibular joint disorder, or snoring. Reduces the burden on teeth and jaws, and also alleviates shoulder stiffness and headaches caused by teeth grinding. Protects the jaw joint muscles and can also be used as a mouthguard to prevent temporomandibular joint disorder.