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The Scuba Club

Established 1972

MK25 EVO/D420 First and Second Stage

1st Stage:

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Combining the iconic design of the original D-Series regulators with the latest advances in breathing performance
technology, SCUBAPRO engineers have created a 21st century regulator in terms of quality, reliability, performance and
style. The new D420 features a brand new balanced valve inside a housing supported by a full metal structure. Called the
Progressive Flow Control Valve, it is able to deliver abundant airflow for the best breathing performance, with a natural
smoothness comparable to what you might experience breathing on the surface. The uniquely shaped fiberglass-reinforced
nylon casing is ultra-durable and allows the LP hose to be connected on either the right or left side for maximum rigging
flexibility. A new dive/pre-dive system includes a switch on the top of the casing with a thumb tab for adjusting the direction
of airflow right out of the valve. The highly efficient purge button is a technical jewel based on a new concept that gives the
D420 its unique face. Teamed with the venerable MK25 EVO balanced piston first stage, this is a regulator system purposedesigned
for today’s avid divers and SCUBAPRO brand enthusiasts everywhere.

First Stage
• Air balanced flow-through piston design delivers consistent
and effortless airflow, regardless of depth, tank
pressure, or breathing rate.
• Patented XTIS (Extended Thermal Insulating System)
fully insulates the inner mechanism from the environment,
improving cold-water resistance by 30% and delaying ice
formation in extreme cold-water conditions without compromising
breathing performance. Key insulation system
components are visible in blue.
• Anti-freeze protection radically increases breathing
reliability when diving in the most extreme water temperatures.
• Two opposing high-pressure ports allow the first stage to
be positioned either up or down.
• Four high-flow and one axial super high-flow low pressure
ports on a swivel turret maximize hose routing options.
• External intermediate pressure adjustment enables technicians
to fine-tune performance quickly and easily.
• Weight (oz/g): INT 232, 27.9/790; DIN 300, 20.1/572.
• Airflow at 2900psi/200bar: (l/min/SCFM): >8500/301.
• Intermediate pressure (psi/bar): 133-142/9.2-9.8.

D420 Second Stage
• NEW. Uniquely shaped fiberglass-reinforced nylon casing
carries on the D-Series heritage with the latest advances
in breathing performance technology.
• NEW. Air-balanced Progressive Flow Control Valve is able
to deliver abundant airflow with a natural smoothness
comparable to breathing on the surface.
• NEW dive/pre-dive system includes a switch on the top
of the case with a thumb tab for adjusting the direction of
airflow right out of the valve.
• NEW casing design features inner winglets that direct
airflow towards the exhaust valve, creating a dramatic
improvement in exhalation effort.
• NEW. Diaphragm is located in the lower section of the
casing to take advantage of the pressure gradient in the
upright position, making breathing even easier.
• Reversible hose attachment allows for either left- or rightside
LP hose connections for maximum rigging flexibility.
• Large purge button is easy to reach and depress, with or
without gloves.
• Exhaust tee is compact and efficiently deflects bubbles
from the diver’s view while enhancing ease of exhalation.
• 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
• CE certified according to the latest EN250A European
Standards for all diving conditions, including extreme
cold water.
• Weight (without mouthpiece): 7.6oz/216g.
• Airflow at 2900psi/200bar: 1800 l/min - 64 SCFM.