MK25

• Air balanced flow-through piston- First stages with air balanced pistons deliver significantly more air to the second stage than any other first stage, while their performance is totally unaffected by the changing tank pressure. A balanced piston allows the use of lighter and more sensitive components, resulting in ultra fast breathing response, instant delivery of air on demand, and extra high air flow, especially in low tank pressure ranges. The tired diver benefits from a smoother breathing regulator during the ascent or deco stop. Balanced piston first stages are the first choice of demanding sport divers and professionals. A balanced piston performs equally in warm and cold water environments.
• Two opposite high pressure ports- The arrangement of high and low pressure hoses is crucial to diving comfort. Two opposite high pressure ports allow for an individual positioning of the first stage (pointing up or down). This allows the diverto position the gauges either on the right or left side and increases the freedom of movement for head and neck.
• Multiple low pressure ports- For ultimate freedom in the arrangement of low pressure hoses, the MK25 accommodates five HF (high flow) ports on a swiveling turret, which allows for 360 degree swivel of hoses. The MK17 and MK11 feature four stationary low pressure ports, two of them HF. High flow ports deliver about 15% more air than conventional ports.
• DIN/INT first stage configurations- To ensure worldwide compatibility, all SCUBAPRO regulator systems are available in a 200bar INT version as well as 300bar DIN versions.
• Externally adjustable intermediate pressure- Allows authorized SCUBAPRO service technicians to quickly fine tune or make adjustments after maintenance without the need to disassemble the first stage.

Cold Water Diving With SCUBAPRO-Diving conditions can be drastically different, including extreme cold water and outside temperatures, posing the possibility of a regulator "freezing". Therefore, resistance to freezing is imperative for the diver. All SCUBAPRO regulator systems are CE approved for 4300psi cold water diving. Some models go even beyond this super stringent qualification and have successfully been tested in extreme cold diving conditions at less than 36°F. As a specific anti-freezing measure, SCUBAPRO engineers have designed a patented finned cap for both the MK17 and the MK25 first stages for optimal cold water diving. The ribs act as a radiator to increase the surface area of heat transfer from the water to warm up the internal parts that have been drastically cooled down by the gas pressure drop. On the MK17, a dry ambient pressure chamber enhances the resistance to real ice cold water at any depth compared to other dry chamber diaphragm first stages. For cold water diving, SCUBAPRO’s second stages feature precision molded carbon fiber and technopolymer valve housing and components. They even exceed the CE cold water norm. In addition, these components contribute to their lightweight features and corrosion resistance.

G250V

• Air-balanced valve technology. The air-balanced valve technology of SCUBAPRO’s second stages features a balancing chamber in the second stage mechanism, slightly offsetting the force of the downstream air entering from the first stage. This allows reduced spring tension and decreases the inhalation resistance to the lowest possible level. The result is super smooth breathing in all conditions. The air-balanced valve technology is featured in the X and S-Series second stages. For best results they should be combined with balanced first stages, like the MK25 or MK17.
• Diver adjustable inhalation effort. This feature enables the diver to adjust breathing effort via an oversized control knob; it is available on the X650, S600, and G250 second stages. All other second stages feature a pre-set inhalation effort that suits the most common diving conditions and can be fine tuned at an Authorized SCUBAPRO Dealer on request.
• Venturi Initiated Vacuum Assist (VIVA). Another SCUBAPRO patented feature, the VIVA is available on all SCUBAPRO second stages. VIVA uses the power of a vacuum assist to reduce work of breathing and increase breathing comfort. It is diver adjustable on all current SCUBAPRO second stages except the R295, since it is a second stage intentionally designed for diver training courses, rental facilities, and divers demanding ready to use equipment. A VIVA in MAX position gives powerful breathing support on every single breath; a VIVA in MIN position helps to prevent free flow on the surface, for training, for buddy breathing, in currents, or when used as an octopus.
• Orthodontic mouthpiece. SCUBAPRO uses a comfortable orthodontic mouthpiece on every second stage to reduce jaw fatigue and gum irritation. It was developed by dentists and dental laboratories and lasts longer than any other mouthpiece, because only a minimum effort is needed to hold it comfortably in place.