MARES 28XR WITH HR - FULL TEK SET REGULATOR DINMares has incorporated the top of modern regulator technology into the 28XR HR underwater regulator. The first stage uses the innovative concept of the balanced diaphragm, which is operated by a double piston. All ecologically sealed using AST Auto Sealing Technology. This also guarantees perfect sealing against the possible entry of sand or particles, especially in cave diving or in polluted waters. This proves further true in technical diving, for