This is the Mares ROVER 15X 1st and 2nd Stage Diving Regulator Features: 1st stage Dfc port Pre-oriented ports Compact size Sandblasted finish 2nd stage Easy-to-use purge button with dynamic hinge design Vad system with fluid dynamic deflector Mid-size Oversized purge button Rubber hose Abrasion resistant and affordable, ideal for diving in warm and moderate water temperatures. Patented design which reduces the impact of water flow onto the second stage diaphragm, thus eliminating free flows even in strong currents. The air bypass tube delivers air to the mouthpiece creating a swirling vortex with a low pressure area in the center that keeps the diaphragm down during inhalation, for very sensitive and easy breathing at all depths. Minimizes intermediate pressure drop during inhalation thus maximizing gas delivery, especially under extreme conditions. Mares ROVER 15X 1st and 2nd Stage Diving Regulator.