This is the Sherwood Magnum Pro Scuba Diving Regulator 1st & 2nd Stage Features: Tee - shaped design reduces regulator profile when mounted on tank minimizing opportunity to make contact with the back of the head. Balanced- piston delivers ample air volume at stable intermediate pressure to the second stage over a wide range of supply pressures. Spring chamber is environmentally sealed to maintain cleanliness reducing the effects of corrosion and contamination. This contributes to uniform high performance as the regulator is used. Dry-sealed first stage uses no liquids or gels that can leak or add to service costs. Four LP ports and two HP ports for more options for ideal hose positioning. Pneumatically balanced 2nd stage - The pneumatically balanced regulator ensures you get the same amount of air delivery whether you are at 3,000 psi or 500 psi, improving the diving experience. Venturi switch - The Venturi switch provides performance adjustments at the surface or at depth, providing a more stable regulator. Single valve tube construction - The single construction creates a precise channel for the valve to operate. Co-Molded mouthpiece - The large co-molded mouthpiece uses two different silicone compounds and colors to reduce jaw fatigue. The new Sherwood Magnum Pro is a completely new designed second stage for better breathing performance, stability, and durability.The Magnum Pro is now a pneumatically balanced 2nd stage regulator. It uses the same technology and design that has earned the Brut worldwide recognition for durability and reliability, bur the Magnum Pro goes a step further with an added Venturi device to reduce breathing resistance at the higher flow rates when it is needed the most. A flow control switch allows the diver to switch the Venturi effect off while at the surface or in shallow water to stabilize the regulator for better manageability.