First Stage:
FSR style first stage.
Highly polished bright chrome plating.
Compact one piece body.
4 angled medium pressure ports, 4 x 3/8 UNF.
2 angled high pressure ports, 2 x 7/16" UNF.
Optional 5th port.
Removable ARCAP valve seat.
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.
An environmental dry system keeps water out of the main spring chamber thus preventing ice buildup and keeping silt and contamination out