Unique over-balanced, diaphragm design – as the diver descends, the over-balancing feature allows the medium pressure gas in the hose to increase at a rate faster than ambient. This results in superior performance at depth. 2 HP ports and 4 MP ports on a rotating turret are angled for optimum hose routing An environmental dry system keeps water out of the main spring chamber thus preventing ice buildup and keeping silt and contamination out.