SCUBAPRO's best-selling air balanced second stage and its top-performing air balanced piston first stage is a match made in diver heaven. Well-known for its low work of breathing, year after year this combo has consistently ranked as one of the top-performing reg systems on the market. The MK25 EVO first stage lets you enjoy an ultra-fast breathing response, instant delivery of air on demand, great sensitivity and impressive airflow. The S600 delivers smooth and easy inhalation and exhalation while offering efficient user controls, including a powerful purge, an inhalation effort control knob and Venturi Initiated Vacuum Assist (VIVA). Together they provide a steady flow of air, regardless of depth, water temperature, or workload.

• Air balanced flow-through piston in a chrome plated brass body provides constant and effortless airflow unaffected by depth, tank pressure, or breathing rate.

• Patented XTIS (Extended thermal Insulating system) thermally insulates the inner mechanism from the environment, improving cold-water resistance and delaying ice formation in extreme cold-water conditions without compromising breathing performance.

• Anti-freeze protection radically increases breathing reliability when diving in the most extreme water temperatures.

• Two opposing high pressure ports allow the first stage to be positioned either up or down.

• Four high-flow and one axial super high-flow low pressure ports on a swivel turret maximize hose routing options.

• External intermediate pressure adjustment enables technicians to fine-tune performance quickly and easily.

• Air balanced second stage valve smoothes out the inhalation effort at varying depths and supply pressures.

• Second stage’s rugged reinforced technopolymer case and front cover with stainless steel frame looks good plus is extremely durable.

• Metal valve housing (barrel) is able to withstand years of aggressive diving.

• User controls include a diver-adjustable inhalation effort knob and Venturi-Initiated Vacuum Assist (VIVA) dive/pre-dive switch.

• Super-flow hose features an oversized bore (larger inside hose diameter) that allows more air to flow on each inhalation.

• Ultra-comfortable orthodontic mouthpiece is easy to grip yet doesn't inhibit airflow.