The Storm Nitrox first stage regulator is compatible with oxygen mixes up to 100%. Storm first stage regulator incorporates the most advanced regulator design. It gives you excellent breathing whether your in the deep or near the surface. Its efficient design gives it an advanced look. It has undergone rigorous pressure testing (300 bar) to ensure its integrity. The design of the valve and the seat of the first stage offer optimal performance under all conditions.  Recommended 2nd Stage: OC350, OC300, OC450, OC400  Advantages: reliable, ideal regulator for dirty water environment and all diving conditions, environmentalized to prevent freeze-up.  Users: ice divers, lake divers, tech divers, pro divers