Feature: 1. Special design mouthpiece to reduce jaw fatigue and increases comfort. Can be easy and repeatedly to shape. 2. Just dip the mouthpiece in hot water, then briefly cool and place into your mouth in the proper orientation. Bite down softly for a good fit of your bite pattern. 3. Suitable for adults. It can be applied for deep-diving, free diving equipment, fits most standard regulators. 4. If there are a little loose, you can use the given tie belt to tie, prevent water leakage. 5. This mouthpiece can hang in your mouth without biting down the mouthpiece tabs that you do not have to use your muscle too much. Specification: Features: Special design mouthpiece to reduce jaw fatigue and increases comfort. Can be easy and repeatedly to shape. Just dip the mouthpiece in hot water, then briefly cool and place into your mouth in the proper orientation. Bite down softly for a good fit of your bite pattern. Suitable for adults. It can be applied for deep-diving, free diving equipment, fits most standard regulators. If there are a little loose, you can use the given tie belt to tie, prevent water leakage. This mouthpiece can hang in your mouth without biting down the mouthpiece tabs that you do not have to use your muscle too much. Specifications: Material: TPE Color: Blue/ Black/ White/ Pink (optional) Size: 7*5*2.5cm/ 2.8*2*1in Weight: 60g/ 2.1oz Package List: 1 * Scuba Diving Mouthpiece Package List: 1 * Scuba Diving Mouthpiece