Atomic's most compact and economical safe second, the Z1 shares the same high performance breathing characteristics and patented design features found in our more expensive models. The second stage features the exclusive Atomic AFC (automatic flow control) for natural effortless breathing at every depth without having to make external adjustments. The critical metal components of the demand valve (lever, orifice and spring) are all made of titanium and are completely corrosion proof. The demand valve housing is machined of brass and plated with an exotic Zirconium plating that outlasts conventional chrome plating by 3-4 times. The combination of high quality materials and the patented Seat Saving Orifice Design result in a regulator that is extremely reliable and trouble-free even in the harshest conditions. A manual override adjustment knob is provided to reduce the regulators sensitivity during entries or exits. Std. with 32 inch hose.