The MK21/S560's size and weight make it an excellent choice for travel divers, its innovative fin design makes it a good cold-water performer, its "smart" hose layout is well-suited for some technical applications, and its overall ease of use, reliability and price make it the must-have reg system for recreational divers of all skill levels.
MK21 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 percent 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, allows 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.
- Available in either 3364psi/232bar INT or 4350psi/300bar DIN configurations.
- Weight: INT 232 (oz/g): 27.5/780; DIN 300 (oz/g): 19.7/560.
- Airflow at 2900psi/200bar: (l/min/SCFM): >7500/265.
- Intermediate pressure (psi/bar): 133-142/9.2-9.8.
S560 Second Stage:
- Air-balanced valve smoothes out the inhalation effort when diving at varying depths and supply pressures.
- Lightweight techno-polymer casing helps Reduce jaw fatigue and improve diving comfort.
- Technopolymer inlet tube contributes to reliability and long life.
- High flow exhaust valve Reduces exhalation effort to lower overall work of breathing.
- 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.
- Weight (without mouthpiece): 5.6oz/160g.
- Airflow at 2900psi/200bar: 1850 l/min - 66 SCFM.