Mares 28XR - HR - Full Side Mount Tek SetMares 28XR HR Full Side Mount Tek Set Mares 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