The Streamlined Openwater Xstream Regulator Package for single tank divers seeking ultra high performance is a Poseidon Xstream "Black" first stage, and two Poseidon Xstream Mk3 second stages together with our DGX premium accessories. The package comes configured with DGX premium double braided flex or rubber hoses and also includes a DIN-to-Yoke spin-on adapter, a DIN regulator cap, and is Nitrox Ready. The primary second stage is on a {40 in | 1 m} flex or rubber hose with an underarm swivel, and the backup second stage is on a {22 in | 57 cm} flex or rubber hose with a necklace, a thin SPG (choice of PSI or BAR) on a {26 in | 66 cm} HP flex or rubber hose with a S/S snap, plus a {22 in | 57 cm} inflator flex or rubber hose for your BC.

The Xstream first stage uses a unique synthetic ruby sphere that virtually eliminates high pressure seat wear that is common in knife edge design seating systems. The Xstream first stage also uses a rolling diaphragm design that eliminates any restriction in movement, which creates a smooth transfer of gas from the first stage to the second stage. This rolling diaphragm design further creates a insulating barrier so there is no need for an additional environmental kit. The Xstream has five low pressure standard 3/8-inch UNF ports and two high pressure standard 7/16-inch UNF ports. The Xstream Black version is Nitrox Ready, incorporating oxygen compatible o-rings and lubricant. The Xstream is CE certified to EN250 European cold water standards.

The low-profile compact Xstream second stage uses pilot-operated upstream demand valve technology that also seals the seat without the use of conventional knife edge design seating systems. This servo-assist feature allows for very low inhalation effort and also eliminates any need for a venturi switch or adjustment knob. The second stage is also ambidextrous, allowing both left and right hose routing and breathes equally well in nearly any swimming position while the side mounted exhaust directs the bubbles out of the field of vision.