This mouthpiece molds to fit your mouth, teeth, jaws & gums. It is scientifically designed by an orthodontist to use your entire jaw for maximum retention & control of the regulator unit. Experience this & say goodbye to jaw fatigue! Fully adjustable & trimmable. Can be remolded. Just heat in hot water & bite down for a fully customized fit. Comes in specific models to fit your brand of regulator.