The MK21 is SCUBAPRO's most compact air balanced piston first stage. It delivers outstanding breathing performance, no matter how hard you're breathing, how deep you're diving or what your pressure gauge reads.
Air balanced flow-through piston first stage 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 redesigned cap protects internal components from water intrusion after the dive.
1st Stage Type Piston
Water Temperature Cold, Temperate, Warm
Connector Type INT
Nitrox Mix Up to 40%
HP Ports 2
LP Ports 4
1st Stage Materials Chrome-Plated Brass