Atomics' most compact and economical regulator system. The Z2 may be the least expensive of the Atomic Aquatics line, but its combination of performance, ergonomics and materials are unmatched by the most expensive competitors at any price. The Z2 is an exceptional value offering all the exclusive Atomic Aquatics performance features and innovations. High performance breathing: High performance (low inhalation efforts at deep depths and high breathing rates) yet delivers the air naturally and comfortably. Materials: The Z2 first stage is made from chrome plated brass and type 316 stainless steel. The second stage features a precision machined brass demand valve tube, plated with Palladium/ Zirconium for corrosion resistance 3-4 times that of conventional chrome plating. The lever, orifice and second stage spring are titanium. Nitrox ready: Factory ready for Nitrox to 40% Compact first stage design: Available in 2 first stage models. An economical 7-port low-pressure fixed cap or a swiveling 5 port cap. Both feature the exclusinve "Jet Seat" first stage piston design. Seat Saving Orifice: Exclusive patented Atomic Aquatics feature prolongs the second stage seat life indefinitely, eliminating aggravating leaks and degradations in performance. AFC: (Automatic flow control) Exclusive patented Atomic Aquatics feature automatically adjusts airflow at depth to maintain stable, comfortable breathing. The warranty is limited lifetime and the service interval is 2 years or 300 dives.