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 purpose-designed for today's avid divers and Scubapro brand enthusiasts everywhere.

Scubapro has been the Leader in the Evolution of piston controlled first stages since its beginning; the MK25 EVO carries on this heritage with an array of patented features ensuring unfailing performance. The MK25EVO is a balanced piston first stage, Scubapro's absolute top performer. It is a superior regulator thanks to its ultra-stable intermediate pressure (IP) resulting in an extremely punctual and constantly high delivery of air. This means instant airflow at any tank pressure and water temperature for a real carefree dive.

Air balanced, flow-thru-piston first stages with air balanced pistons deliver significantly more air to the second stage than any other first stage, while their performance is totally unaffected by the changing tank pressure. A balanced piston allows the use of lighter and more sensitive components, resulting in ultra-fast breathing response, instant delivery of air on demand, and extra high air flow, especially in low tank pressure ranges. The tired diver benefits from a smoother breathing regulator during the ascent or deco stop. Balanced piston first stages are the first choice of demanding sport divers and professionals. A balanced piston performs equally in warm and cold-water environments.

The MK25 EVO has two opposite 7/16" threaded high-pressure ports (HP). The arrangement of high and low-pressure hoses is crucial to diving comfort. Two opposite HP ports allow for an individual positioning of the first stage (pointing up or down). This allows the diver to position the gauges either on the right or left side and increases the freedom of movement for head and neck. Multiple low-pressure ports (LP) - For ultimate freedom in the arrangement of LP hoses, the MK25 EVO accommodates five HF (High Flow) 3/8" threaded ports on a swiveling turret, which allows for 360° swivel of hoses. High flow ports deliver about 15% more air than conventional ports. Externally adjustable intermediate pressure- allows authorized Scubapro service technicians to quickly fine-tune and adjusts the first stage after maintenance without the need to disassemble it.

Cold Water 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. The MK25 EVO regulator uses Scubapro's new Extended Thermal Insulating System (XTIS). The Scubapro MK25 EVO first stage regulator meets the new EN250-2014 requirements for cold water diving, CE approved for 3360psi (230 bars). This model goes even beyond this super stringent qualification and has successfully been tested in extreme cold diving conditions at less than 36°F (2.2°C). The freezing resistance has been increased by 30% over the previous MK25 regulator first stage. Scubapro has achieved this with some new design features. The new MK25 EVO has a proprietary thermal insulating coating on key internal components and an encapsulating main spring bushing that resist the cooling effect in previous MK25 first stage regulators, also as a specific anti-freezing measure; Scubapro engineers have designed a patented finned cap with additional body fins for the MK25 EVO first stages for optimal-cold water diving. The fins (ribs) of the XTIS 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 new MK25 EVO has a bigger body cap, new body with insulating bushing and ribs, new antifreeze cap patented isolation system with all internal parts fully insulated to dramatically improve cold water performance.

This system now gives the diver superior cold-water performance, equal to that of Scubapro's MK17 first stage. Now you have the option of a high-performance flow through piston design, with a high level of performance in cold water. This is the answer for those divers who demand a high level of performance for cold water environments. The MK25 EVO is manufactured from marine grade chrome plated brass and offers a balanced composite/stainless steel flow-thru piston that would make any diver proud. It demonstrates Scubapro's dedication to quality and creating positive diving experiences.

The Scubapro D420 second stage regulators uniquely shaped fiberglass-reinforced nylon casing carries on the D-Series heritage with the latest advances in breathing performance technology. Air-balanced Progressive Flow Control Valve is able to deliver abundant airflow with a natural smoothness comparable to breathing on the surface. 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. Casing design features inner winglets that direct airflow towards the exhaust valve, creating a dramatic improvement in exhalation effort. 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-right-side 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 3/8" threaded 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 smallest. Regulator weighs 40.8 oz. (1,157 g), is Nitrox compatible up to 40% oxygen and comes with an owner's manual.

Scubapro MK25 EVO/D420 Regulator, Yoke Features

• Scubapro MK25 EVO/D420 Regulator, Yoke:
• High Performance, Reliable Scubapro Technology and Value
• Superior Ultra-High Airflow System
• Maximum Performance in All-Temperatures & Conditions
• 3/8" Threaded Oversized Bore Low-Pressure Super Flow Hose
• More Air On-Each Inhalation
• Nitrox Compatible Up to 40% Oxygen
• Weight: 40.8 oz. (1,157 g)
• Owner's Manual
• Scubapro Mark 25 EVO Regulator Yoke, First Stage:
• Superior Cold-Water Performance Equal to Scubapro's MK17 First Stage
• EVO: Means Evolution, Revolutionizing Existing Technologies to Higher Performance
• High Performance, Reliable Scubapro Technology and Value
• Superior Ultra-High Airflow System, Maximum Performance in All-Temperatures & Conditions
• Ultra-Stable Intermediate Pressure
• High Performance in Warm and Cold Water to 3336 psi (230 bars)
• Meets New EN250-2014 Requirements
• CE Approved for 3360 psi (230 bars) in Cold Water Conditions
• Increased Cold Water Efficiency by 30% Over Previous MK25 Regulator
• New Design:
  Proprietary Insulating Coating On-Key Internal Components
  Specific Anti-Freezing Measure
  Patented Finned Cap and Body
  Xtreme Thermal Insulating System (XTIS)
  Ribs of XTIS: Act as Radiator, Increase Surface Area of Heat Transfer
  Warms-Up Internal Parts
• New Parts:
  Bigger Body Cap
  Insulating Bushing
  Antifreeze Cap
  Patented Isolation System
  Internal Parts Fully Insulated to Dramatically Improve Cold Water Performance
• Air-Balanced Flow-Through Piston Design
• Balanced Composite/Stainless Steel Flow-Thru-Piston
• HP Ports: Two 7/16" Threaded
• LP High Flow (HF) Ports: Five 3/8" Threaded
• LP Ports Mounted on Swivel Turret Cap for Maximum Hose Routing
• Scubapro D420 Second Stage Regulator:
• Uniquely Shaped Fiberglass-Reinforced Nylon Casing
• Carries-On D-Series Heritage w/Latest Advances in Breathing Performance Technology
• Air-Balanced Progressive Flow Control Valve
• Delivers Abundant Airflow w/Natural Smoothness Comparable to Breathing On-Surface
• Dive/Pre-Dive System: Switch On-Top of Case w/Thumb Tab Adjusting
• Casing Design Features Inner Winglets: Direct Airflow Towards Exhaust Valve
• Winglets: Create Dramatic Improvement In-Exhalation-Effort
• Diaphragm:
  Located In-Lower Section of Casing
  Takes Advantage of Pressure Gradient in Upright Position
  Makes Breathing Even Easier
• Reversible Hose Attachment: Allows Left-or-Right-Side LP Hose Connections
• Maximum Rigging Flexibility
• Large Purge Button: Easy to Reach & Depress, with or w/o Gloves
• Compact Exhaust Tee:
  Efficiently Deflects Bubbles-From-Diver's-View
  Enhances Ease of Exhalation
• High Comfort Orthodontic Mouthpiece:
  Improves Airflow & Mouth Comfort
  Fits All Mouth Sizes
  Largest to Smallest