Premium Medical Grade Material: Made of silicone material, non toxic and safe to use. Good shape stability. After immersing in boiling water for a long time, the brace will not be seriously deformed or contracted. Advantage: With Good thermoplasticity that each dental duty mouth guard is easily trimmed to fit any mouth size. Can be adapted to fit a wide variety of teeth alignments, tooth sizes & mouth shapes for optimal comfort. Reusable and moldable: It can be repeatedly molded without worrying about the deformation of the braces caused by improper use. Suitable for home use, the gum line is very clear.