This is the Scubapro S620 Ti Titanium Second Stage Scuba Diving Regulator Features: Scubapro's Top Performer Embraces Best of Scubapro's Renowned S600 Upgraded, State-of-the-Art Design Smaller and Lighter than S600 Unparalleled Breathing Performance Work of Breathing Reduced by 37% Over the S600 Effortless Airflow Under All Dive Conditions Linear Air-Balancing Valve Top-Notch Air-Balancing System Diver Adjustable Inhalation Effort for Personalized Breathing Control The new S620 Ti embraces the best features of Scubapro's renowned S600 in an upgraded, state-of-the-art design. Smaller and lighter than the S600 but using the same-sized diaphragm, the S620 Ti delivers excellent performance; work of breathing has been reduced by 37% over the S600, providing effortless airflow under all dive conditions. The full titanium inlet tube is ultra-light, the large purge button improves water circulation, and the new exhaust tee increases performance while directing bubbles out of the field of view. In all water temperatures, in all dive conditions, this new regulator system is a winner. Because of the S620's versatility, it can meet the diver's needs as frequently as the diver changes dive sites. The S620 valve housing is constructed from lightweight titanium. The S620 has a linear air-balancing valve, and a top-notch air-balancing system. This regulator's air-balanced linear-flow valve allows the diver to use less energy while breathing underwater; it makes breathing during a dive as simple as well, breathing in and out!