Zeagle's Envoy II Yoke First Stage Regulator was the only regulator in its price class to earn perfect simulator scores, even at the most demanding RMV/ Depth. It also delivered far and away the best in-water performance. Zeagle's regulators are US made, built under strict controls for quality in Zeagle's own factory, using state of the art equipment and procedures. Your regulator is one of your most important pieces of gear. No matter what kind of diving you do, you can do it better with Zeagle. The Zeagle Envoy II first stage regulator has an internal structure that allows for direct airflow through the 1st stage, providing outstanding performance. Zeagle's conical precision stainless steel high-pressure valve and advanced polymer seat provide much greater reliability and service life compared to conventional designs, while improving responsiveness and Performance at all breathing rates. High performance porting in a balanced diaphragm design makes this one clean regulator first stage that will give you years of corrosion free service. The first stage regulator has 5 low pressure (LP) ports 3/8"-24 UNF thread and 2 high pressure (HP) ports 7/16"-20 UNF thread. Regulator weighs 30.1 oz. (852.75 g), and is Nitrox ready to 40% out of the box.