C shape design: - Ergonomic in use, strong anastomosis in the mouth. Helps you get an unobstructed view of the oral cavity.High-quality materials: - 11.8 * 8.5 * 1.7 cm (medium size), 12 pieces in a set, made of polycarbonate in medical quality. The edges are smoothed and comfortable to wear.Protect your oral health: - They are often used in home teeth whitening procedures to open the mouth and keep the whitener away from the lips and gums.Playing methods: - Put one of these mouth openers and try to say a challenge phrase while you cant close your lips. Let your partner understand what you want to say and the fun begins.Recyclable: - You can save money in the long run with a robust, fully recyclable material. And if you have any questions about the product, please contact us. We will give you a satisfactory solution.