The Z Series Second-Stage is a Balanced Linear Flow Design for Extremely Easy Breathing at all Depths and Dive Conditions. The Z Series Second-Stage is Built-to-Last with a Zirconium Plated Brass Demand Valve Body, Titanium Lever and Sealing Orifice. The Diaphragm is made from High Quality Silicone Rubber. This Pneumatically-Balanced Poppet Second-Stage has Atomics Patented Seat Saving Dynamic Orifice which unlike most Second-Stage Orifices is a Floating Valve Design which Reduces Wear on the Second-Stage Poppet Seat when the Regulator is not pressurized adding Life to this Important Seal.