Atomic Aquatics Dual-silicone Comfort-fit Regulator Mouthpiece. At Atomic Aquatics, their engineers and award-winning designers are always listening to diver's requests for product upgrades and enhancements. One such request was for a mouthpiece that would be both durable and comfortable. The result is the popular dual-silicone mouthpiece that was introduced with the M1 regulator. Made from two types of silicone material, this mouthpiece is incredibly durable, yet easily one of the most comfortable mouthpieces a diver will ever use.