TookieScuba Diving Mouthpiece, Denpetec Scuba Diving Mouthpiece, Practical Gear Silicone Bite Moldable Scuba Diving Dive Mouthpiece Regulator with Tie Wrap for Adults(Black)

This is great, I'm using it on a cressi compact regulator, I put the mouthpiece in warm water for 1min then bit on it for around 2 to make it form around my teeth, after I cut off the excess material that was touching my gums and its been perfect every since, it says in place with no effort when scuba diving no biting or jaw fatigue