The Flow-by Piston design of the RaZor 1st stage provides much greater reliability and serviceabilty compared to conventional designs, while improving responsiveness and performance at all breathing rates. This 1st Stage sits direct atop a Tank Valve section the threads into any standard 3/4-14 NPSM Scuba Cylinder. This combination saves space and increases efficiency making it ideal where weight and space are critical such as stage bottles and fully redundant systems. The RaZor comes with a filling adapter that allows the RaZor to fill its tank using a standard Yoke Filling Whip. Work of breathing at heavy demand*: 1.34 Joule/Liter *198' (60M) depth, 750 psi inlet, 62.5 RMV (liters per minute respiratory volume) RaZor FIRST STAGE/VALVE FEATURES: High Performance Porting Flow-by Piston Yoke Style Filling Adapter Included 4 Low Pressure Ports (3/8”-24 UNF) 1 High Pressure Port (7/16”-20 UNF) Weight 1.62 lb. (.73 kg.) Intermediate Pressure: 125-150 psi (8.6-10 bar) First Stage Materials: Body: Brass O-rings: Buna-N Seat: Advanced Polymer HP Seat: Teflon Valve Seat: Teflon ENVOY SECOND STAGE FEATURES: Downstream valve Balanced Diaphragm Dive/Pre Dive Venturi Control Weight: .42 lb. (.26 kg) ( w/o hose) Hose Length: 44 in. (1.1 m) Second Stage Materials: Cover: Flexible Thermoplastic Case: Thermoplastic Poppet Seat: Elastomer O-Rings: Buna-N Diaphragm: Elastomeric Polymer Exhaust Valve: Elastomer Mouthpiece: Silicone Like all Zeagle regulators, The Envoy RaZor comes factory ready for use with EAN/ NITROX to 40% O2. More Resources: Filling the RaZor's Cylinder A comparison chart showing all Zeagle regulators Information on Alternate Air sources Popular Regulator Accessories. A printable PDF Data Sheet on the Envoy RaZor regulator. RaZor Owner's Manual Breathing Performance Chart for the Envoy RaZor