A truly modern regulator from IST with the performance to match.With its Tester Approved O-10 second stage the R-410 delivers unparalleled performance irrespective of depth. The R-4/N 1st stage is a brand new balance diaphragm design with outstanding flow characteristics.R-4 is capable of keeping intermediate pressure steady and remains unaffected by depth or remnant tank pressure.2 Fixed high pressure ports and 4 low pressure ports on swivel turret for better hose configuration.All condition environmental seal protects the internal components of the first stage from slit harmful contaminant and extreme cold.Air is the chosen medium used in all condition environmental seal as it is the most effective barrier. The pneumatically balance second stage with stainless rocker arm to give efficient air deliver on demand.The flow adjustment knob can be tuned infinitely to meet any gas flow volume demand at any time during a dive operation.The special air foil atop the casting is intended to provide smooth air supply ' ' position or to help the diver to conserve air '-' position by physically encouraging long and slow breathing.Equipped with MP5 mouthpiece its special shape and long biting tabs significantly lessens jaw fatigue during a dive. Features a built-in heat exchanger and light purging action.