You cannot breathe directly out of a scuba tank because of the high pressure. A regulator reduces pressure to safe a level that can be inhaled by the diver. A diving regulator has two parts: the First Stage reduces the tank pressure and connects it to the Second Stage which contains the mouthpiece for breathing
A STAND-OUT ALL-PURPOSE REG SYSTEM SCUBAPRO's best-selling air-balanced second stage and its top-performing air-balanced piston first stage is a match made in diver heaven. The high performance MK25 EVO/S600 reg system is well-known for its low work of breathing and tremendous reserve capacity. Year after year it is consistently ranked as one of the top-performing regs 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 extra-high airflow -- regardless of how cold the water is. This is made possible with SCUBAPRO's exclusive patented Extended Thermal Insulating System (XTIS) that fully isolates the mechanical elements of the first stage from the cold, increasing its freezing resistance 30 percent over previous versions of the MK25 without compromising breathing performance. This makes the MK25 EVO the ultimate do-it-all first stage for all water temperatures. The S600, with its rugged fiberglass casing and stainless steel front face and ring, 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) dive/pre-dive switch. It provides a steady, effortless flow of air, regardless of depth or workload. Now you can spice up your MK25 EVO/S600 system with interchangeable S600 purge covers in a choice of colors (Blue, White, Yellow, Red and Pink). Pick a color that celebrates your diving style! Synonymous with SCUBAPRO quality and unbeatable engineering, the MK25 EVO/S600 is the preferred combo of professionals. In all water temperatures, in the most demanding dive conditions, this reg performs flawlessly.
Air balanced flow-through piston in a chrome-plated brass body.
Patented XTIS (Extended Thermal Insulating System) fully isolates the mechanical elements from the cold,
New spring insulating coating, body insulating bushing, anti-freeze cap, bigger body and cap thread.
Two opposing high pressure ports allow the first stage to be positioned either up or down.
Five high-flow low pressure ports on a swivel turret maximize hose routing options.
External intermediate pressure adjustment.
Metal valve housing (barrel) is able to withstand years of aggressive diving.
Air-balanced valve smoothes out the inhalation effort when diving at varying depths and supply pressures.
Super-flow hose features an oversized bore
Ultra-comfortable orthodontic mouthpiece is easy to grip yet doesn't inhibit airflow.