This is the XS Scuba Inspire 2nd Stage Only Scuba Diving Regulator Features:2nd Stage Pneumatically-balanced to provide superior breathing performance The Inhalation Control Knob adjusts the inhalation effort An integrated venturi lever allows the diver to turn off the venturi when the regulator is out of the mouth The 30 Miflex braided hose is lightweight and pliable Comes with upgraded, extended-tab mouthpiece for jaw comfort The Inspire is a performance regulator. It provides superior breathing. It breathes dry in all positions. It breathes quietly and smoothly. It proves that you do not have to pay top dollar to get performance and features. Factory cleaned and ready for pre-blended Nitrox up to 40% oxygen. The Inspire is for use in water >50° F (10° C)."