Quick Overview The ultra-compact MK21/C370 regulator system delivers the ideal blend of comfort and performance. The R095 octopus regulator is about as simple as can be, yet delivers air reliably when needed. Scubapro MK21 First Stage is a compact, balanced piston-controlled first stage with exceptional Scubapro breathing performance at a mid range price. Compact sized (16mm smaller than the MK25) but not in features, this modern, edge-design first stage has a smart hose layout for perfect positioning and easy identification. The high air flow delivery to the second stage ensures unaffected breathing effort, no matter the tank pressure or depth.  The MK21 also has a good cold water performance for a compact first stage, due to the external fins which optimize thermal exchange. Scubapro MK21 / C370 / R095 Octopus Set About 20% smaller than SCUBAPRO\'s flagship MK25 but benefitting from the same core technology, the MK21 features a modern, cutting-edge design whose size and weight make it an excellent choice for travel divers. Simple and reliable, the air balanced C370 delivers consistent airflow, ease of use and dependability, making it just the ticket for recreational divers in general, and dive travelers in particular. Thanks to its compact size and lightweight, this is also a fantastic regulator for our female divers and smaller sized divers. With any of these regulator systems in your dive bag, you\'ll be ready to hit the road. Together they create a no-nonsense air delivery system that delivers big performance in a small package. The R095 is a new economical second stage featuring classic downstream valve technology that has a well-earned reputation for safety and reliability. Designed to be extremely easy to use in an emergency, the R095 is pre-tuned to the optimum inhalation volume for safe and uncomplicated use -- you never have to hassle with control knobs or switches; simply put it in your mouth and breathe. The R095 OCTO combines all the features of the R095 with a high-visibility yellow purge cover and a 39-inch yellow hose that makes it that much easier to share with a buddy in need. For new divers as well as veterans looking for an economical backup breather that\'s simple, dependable and offers excellent visibility, the R095 OCTO is a great choice. First Stage: Air-balanced flow-through piston provides constant and effortless airflow unaffected by depth, tank pressure, or breathing rate. Polished chrome-plated marine grade brass body is close to 20% smaller than the MK25, making it an easy travel companion. Unique thermal exchange design with external fins optimizes freezing resistance. Two high-pressure ports, one on each side of the body, allow the first stage to be positioned either up or down. Standard \"smart\" hose routing cap offers four low-pressure ports angled for more convenient hose routing (+/- 20º). Optional hose routing cap increases routing configurations with four angled low-pressure ports (0°/30°) plus a fifth centralized high-flow low-pressure port, ideal for technical diving. Redesigned yoke allows for easier mounting on a cylinder, and a redesigned cap protects components from water intrusion after the dive. Weight: INT 232: 780G; DIN 300; 570g. Airflow at 200bar: (l/min): >7500. Intermediate pressure: 9.0-9.8 bar   R095 Octopus Features a classic downstream valve for optimal breathing performance. Preset inhalation and Venturi-Initiated Vacuum Assist (VIVA) provides hassle-free air delivery. Metal valve housing is built rugged and increases overall reliability. Yellow super-flow hose is 39 inches long and features and oversized bore to increase airflow. Ultra-comfortable orthodontic mouthpiece is easy to grip yet doesn\'t inhibit airflow. Weight (without mouthpiece): 5.0oz/141g. Airflow at 2900psi (l/m/SCFM): 1400/50. Second Stage: Air-balanced valve for smooth inhalation effort at varying depths and supply pressures. Compact rugged fiberglass reinforced nylon casing and new exhaust tee take up little space in a dive bag. Stainless steel frame on the front cover adds the SCUBAPRO signature. The poppet and lever allow the design to maintain the same overall size as the C350. The exhaust tee is based on the S620 Ti\'s design and contributes to better work of breathing (a 10% improvement over the C350). User controls include a diver-adjustable inhalation effort knob and Venturi-Initiated Vacuum Assist (VIVA). Large purge button is easy to activate, even wearing thick gloves. Super-flow hose features an oversized bore that allows more air to flow on each inhalation. Compact Hi-Flow mouthpiece improves airflow as well as mouth comfort, fitting all mouth sizes, from largest to smallest. Weight: 171g. Airflow at 200bar: (l/min): 1600 bar