Mares Fusion 52X Scuba Diving Regulator ACT Valve - Advanced Coating Technology Advanced Coating Technology The new valve in the X systems increases durability by an astounding 600%, even under the most extreme conditions. All Metal Technology Outstanding mechanical reliability and high thermal conductivity make our metal 2nd stages extremely long lasting and ideal for cold water dives. The high thermal conductivity of metal reduces also the dry mouth feeling during the dive. VAD - Vortex Assisted Design 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. Twin Power New, flow control manages the delivery rate of your gas, from natural breathing to power breathing. The former is the traditional way of breathing a Mares regulator, (VAD) while the latter (VAD+) provides an extra push when you need it Superflex Hose Extreme light weight and exceptional softness guarantee the maximum freedom of movement.