100% brand new mouth protector non-toxic and odorless 100% POE high density structure, soft and firm heating snapin design, more fit shape of users' teeth and the mouth guard can reach the rear molars, to provide complete protection. Groove adjust the surface of the teeth, convenient to maintain gentle breathing and will not affect the protective effect of the teeth during strenuous exercise. excellent for Boxing, Kicking, MMA, Fighting, Muay Thai, San-da, Taekwondo, Fire Fighting, Jiu-Jitsu and other vigorous exercises. how to use put the protective teeth into the hot water cup (60 degrees to 70 degrees) until softening for about 10-15 seconds. since it is soft, insert it to the upper teeth in the mouth. to memorize your cast for teeth, bit that by 10-15 seconds. if the protective teeth fits into your mouth, wipe it with water and use it if the protective teeth does not fit into your mouth, you can correct it again from step 1.