The H-50D is a high performance diaphragm design that is fully sealed and purpose-built for harsh conditions, such as ice or environmentally contaminated environments. Diaphragm first stages are historically popular with cold water divers, and the H-50D was engineered for extreme conditions. Go dive extraordinary places with your H-50D, and be confident that you have a rugged regulator that will meet all your demands. Balanced, environmentally sealed diaphragms provide better performance in cold water than any other diaphragm regulator, while supplying consistent performance at varying tank pressures and depths. You will enjoy smooth, easy breathing throughout your dive. The dry, balance chamber diaphragm design prevents the entry of water into the first stage mechanism and enhances a trouble-free operation. This is true even in the coldest conditions. Two opposing high pressure ports allow you to choose where to route your SPG and allows the use of accessories. Most Halcyon divers rou