The M1 Second-Stage is a balanced linear flow design for extremely easy breathing at all depths and dive conditions. The M1 is designed for cold water diving featuring thermal heat sink and improved super-dry exhaust valve. The M1 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.