Scubapro MK21 Yoke First Stage

The Scubapro MK21 300 Yoke is a compact sized piston-controlled first stage. Close to 20% smaller than our MK25, MK21 is a mid-range piston 1st stage offering the best compromise for the right price and the right performance.

Unique thermal exchange design with external fins, optimizing freezing resistance. The optional replaceable head allows for optimal positioning with 4 LP routing configurations (0°/30°) and a central LP HF port. Ideal for Technical diving. Uses the new re-designed yoke and protection cap.

The MK21 First Stage offers the best compromise for the right price and the right performance with ease of maintenance. 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 3336 psi (230 bars) 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 3.9°F (3.9°C). As a specific anti-freezing measure, Scubapro engineers have designed a patented finned cap for the MK21 First Stages for optimal cold-water diving. This finned cap is a Thermal Insulating System (TIS). The ribs of the TIS 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.

The MK21 is manufactured from marine grade chrome plated brass, has a balanced composite/stainless steel flow-thru piston and with the standard head it has 4-HF (High Flow) 3/8″ threaded low-pressure (LP) ports with hose routing at +/- 20° angles and 2 high-pressure (HP) 7/16″ threaded ports, one on each side of the body. The MK21 First Stage weighs 26.2 oz. (744 g) with externally adjustable intermediate pressure which allows authorized Scubapro service technicians to quickly fine-tune and adjusts the first stage after maintenance without the need to disassemble it.


MK21 First Stage: The Best Compromise for Right-Price and Right-Performance with Ease-of-Maintenance.

  • New Compact-Sized Piston-Controlled First Stage
  • Close to 20% Smaller than SCUBAPRO’s MK25 making it great for travel
  • Mid-Range Air Balanced, Flow-Thru-Piston-First Stage
  • Ultra-Fast Breathing Response