This combo offers outstanding breathing performance, plus it's loaded with features that enhance cold-water diving.
The MK21/G260 is a high performance reg system on steroids. It may be positioned in the mid-range of Scubapro's regulator lineup, but it behaves like a front-runner with its ability to handle any diving scenario with power to spare.
The MK21 is Scubapro's most compact balanced-piston first stage. Smaller and lighter than the MK25, it uses a smaller piston but it delivers the same level of breathing performance, no matter how hard you're breathing, how deep you're diving or what your pressure gauge reads. The MK21 also provides exceptional resistance to freezing due to the thermal exchange produced by the external fins on its polished chrome brass body.
The MK21's innovative "smart" hose layout comes with a standard cap with four low pressure ports angled (+/- 20º) to maximize hose routing. This standard cap can be replaced with an optional cap that offers four low pressure ports at more extreme angles (0°/30°) plus a fifth centralized high-flow low pressure port -- a useful configuration for technical diving.
The G260 is the most imitated air balanced second stage design of all time. First introduced in 1986 as the G250, it was the first regulator to introduce an adjustable Venturi Initiated Vacuum Assist (VIVA). Today's modern version features metal components (inlet tube, orifice, inhalation control knob and hose connector) for excellent cold-water performance. It also offers a left-right hose attachment option, making it a great choice for tech diving configurations.
When you put them together you get a super-charged breathing system that's surprisingly affordable. It's a proven performer for all types of diving, but where the MK21/G260 really excels is in cold-water diving scenarios and technical applications.
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): 26.2/744; DIN 300 (oz/g): 19.6/555.
- Airflow at 2900psi/200bar: (l/min/SCFM): >7500/265.
G260 Second Stage:
- Nylon fiberglass design features Scubapro's largest second stage casing and diaphragm for the ultimate in breathing sensitivity, regardless of position in the water.
- Metal components, including metal air barrel and metal valve inlet tube, increase resistance to freezing when diving in extreme conditions.
- Air-balanced valve smooths out the inhalation effort when diving at varying depths and supply pressures.
- High-flow exhaust valve reduces exhalation for better overall breathing comfort.
- Diver-adjustable inhalation effort knob fine-tunes air delivery to suit personal tastes.
- Venturi-Initiated Vacuum Assist (VIVA) dive/pre-dive switch prevents free flows in cold water or when used as an octopus.
- Reversible hose attachment allows you to easily adjust hose routing for tech diving configurations.
- 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: 9.7oz/275g.
- Airflow at 2900psi/200bar: 1800 l/min - 64 SCFM.