Scubapro MK 25 Evo / D420 Dive Regulator System
Scubapro MK 25 Evo / D420 Dive Regulator System - INT is backordered and will ship as soon as it is back in stock.
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Product Information
The SCUBAPRO MK25 EVO/D420 is a two-stage scuba regulator system that pairs the MK25 EVO balanced-piston first stage with the D420 second stage, built with a chrome-plated brass first-stage body, a reinforced technopolymer second-stage casing, and nitrox compatibility up to 40 percent. It is designed for divers who want a balanced-piston regulator with cold-water features and a second stage that can be rigged with the LP hose on either side.
Who it is for
This system suits SCUBAPRO regulator owners who need a balanced-piston first stage paired with a full-metal, balanced second stage. The D420 second stage is designed to pair with either the MK19 EVO or the MK25 EVO first stage, and the LP hose can be connected to the right or left side of the second-stage housing for flexible rigging. The first stage's XTIS thermal insulation and anti-ice mechanism are built for cold-water use, and the system is CE certified to the EN250A European standard for all diving conditions, including very cold water.
Key details
- MK25 EVO first stage: balanced piston design, chrome-plated brass body, 2 high-pressure ports, 5 low-pressure ports (4 high-flow plus 1 ultra-high-flow axial outlet on a rotating turret)
- Air flow at 200 bar: greater than 8,500 L/min at the first stage, 1,800 L/min at the second stage
- Mid-pressure: 9 to 9.8 bar
- D420 second stage: balanced valve in a full-metal structure, Progressive Flow Control poppet, reinforced fiberglass-nylon casing, dive/pre-dive switch with a thumb tab, large ergonomic purge button, and a Compact Hi-Flow mouthpiece sized for all mouth sizes
- Nitrox compatibility up to 40 percent
- Weight: 2.55 lb (216 g without mouthpiece); dimensions approximately 18 cm long, 23 cm wide, 8 cm high
Compatibility and sizing
This system is available with an INT connector or a DIN connector. The D420 second stage is built to pair with either the MK19 EVO or the MK25 EVO first stage.
What's in the box
- MK25 EVO first stage
- D420 second stage
- Compact Hi-Flow mouthpiece
DiveCatalog.com is an authorized SCUBAPRO dealer and a dive shop in Irvine, California, since 2003. Call or chat with us at 888-701-4017 if you have questions about connector type, fit, or compatibility with your current setup.
- Balanced piston first stage with a chrome-plated brass body for the MK25 EVO.
- XTIS thermal insulation is a patented system built into the first stage for cold-water performance.
- Anti-ice mechanism supports the first stage's cold-water performance.
- Two high-pressure ports plus five low-pressure ports, including four high-flow ports and one ultra-high-flow axial outlet on a rotating turret.
- Progressive Flow Control poppet valve in the D420 second stage for a natural breathing sensation.
- Full-metal balanced valve structure inside the D420 second-stage housing.
- Reinforced fiberglass-nylon casing on the second stage allows the LP hose to be connected on either the right or left side.
- Dive/pre-dive switch with a thumb tab on top of the casing adjusts the direction of airflow.
- Large ergonomic purge button is positioned for easy access on the D420.
- Compact Hi-Flow mouthpiece included and sized to fit all mouth sizes.
- Nitrox compatible up to 40 percent oxygen.
- CE certified to the EN250A European standard for all diving conditions, including very cold water.
| 1st Stage Type | Piston |
| 1st Stage Material | Chrome-plated brass |
| 1st Stage Features | XTIS |
| 2nd Stage Design | Balanced |
| 2nd Stage Material | Reinforced technopolymer coating |
| Intake Tube Material | Technopolymer |
| Connector Type | INT, DIN |
| Nitrox Compatibility | Up to 40% |
| HP Ports | 2 |
| LP Ports | 5 |
| Mid-Pressure | 9 to 9.8 bar |
| Air Flow at 200 bar (1st stage) | Greater than 8,500 L/min |
| Air Flow at 200 bar (2nd stage) | 1,800 L/min |
| Adjustable Breathing Effort | No |
| 2nd Stage Features | Compact high-flow mouthpiece, super-flow hose, adjustable VIVA |
| Mouthpiece Included | Yes |
| Product Length | 18 cm |
| Product Width | 23 cm |
| Product Height | 8 cm |
| Weight | 2.55 lb (216 g without mouthpiece) |
- MK25 EVO first stage
- D420 second stage
- Compact Hi-Flow mouthpiece
⚠️ WARNING: This product contains chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm. For more information, visit www.P65Warnings.ca.gov.
Frequently Asked Questions
How often does a scuba regulator need servicing?
Follow the interval in your regulator's manual, since manufacturers commonly specify an annual inspection or a set number of dives and many warranties depend on it. A regulator is life-support equipment, so service belongs with a factory-trained technician rather than being attempted at home. Have it looked at sooner than scheduled if you notice increased breathing effort, free-flow, bubbles, or water in the second stage.
How do I rinse and care for a regulator after diving?
Make sure the dust cap is dry and firmly seated over the first-stage inlet before the regulator goes anywhere near water, because water inside the first stage is the leading cause of internal corrosion. Rinse in fresh water without pressing the purge button, since purging while depressurized can draw water back into the second stage. Shake out the water and hang it to dry with the hoses in wide, gentle loops rather than tight bends.
Can I fly with a scuba regulator?
Regulators travel well and are usually best carried in hand luggage where they will not be crushed or lost. A regulator holds no gas of its own, so there is nothing inherently problematic about it on an aircraft, though the airline and security screeners always have the final say. Pack it dry with the dust cap in place, in a padded regulator bag or wrapped in soft gear.
Can I use my regulator with nitrox?
Many modern regulators are supplied as suitable for nitrox mixes up to 40 percent oxygen, which is the widely used recreational industry standard, while anything above that requires dedicated oxygen-clean equipment and procedures. Confirm what your specific regulator's manual states, and follow your nitrox training and your fill station's requirements. Never assume a regulator is oxygen-service clean simply because it looks clean or is new.
What is the difference between DIN and yoke regulators?
A yoke (A-clamp) fitting clamps over the tank valve and is the most common connection across much of the recreational world, while a DIN fitting screws into the valve and is standard in much of Europe and in technical diving. DIN captures the o-ring inside the threads, which many divers consider more secure, but yoke is often what rental cylinders provide. Adapters exist in both directions, so check what is used where you dive before deciding.
What is the octopus regulator for?
The octopus is your backup second stage, carried so you can share air with a buddy who is out of gas, or breathe from it yourself if your primary fails or free-flows. It is normally on a longer, brightly colored hose so it is easy to find and hand over under stress. Secure it in the triangle between your chin and the bottom of your rib cage so it is instantly accessible and not dragging through sand or coral.
How should I store a regulator between dive trips?
Store it fully dry, out of sunlight, with the dust cap in place and the hoses in wide loops rather than tightly coiled. Avoid hanging it by the second stages for long periods, which stresses the hose fittings; laying it flat in a padded bag or hanging it by the first stage is kinder. If it has sat unused for a long stretch, have it checked before your next trip rather than assuming it is ready to dive.
Does the D420 second stage work with other SCUBAPRO first stages?
Yes, SCUBAPRO's own product information states the D420 second stage is designed to pair with either the MK19 EVO or the MK25 EVO first stage. This regulator system comes pre-matched as an MK25 EVO/D420 set, so if you already own an MK19 EVO or MK25 EVO first stage, the D420 second stage is a compatible pairing.
What connector options does the MK25 EVO/D420 come in?
This regulator system is available with either an INT connector or a DIN connector. Choose the connector that matches your scuba tank valve, since INT (yoke) and DIN fittings are not interchangeable without an adapter. Contact DiveCatalog.com if you are unsure which connector your tank or travel destination requires.
Is the MK25 EVO/D420 built for cold-water diving?
Yes, the MK25 EVO first stage includes the patented XTIS thermal insulation system and an anti-ice mechanism for cold-water performance. The system is also CE certified to the EN250A European standard, which covers all diving conditions including very cold water.
How much does the MK25 EVO/D420 weigh?
The manufacturer lists the weight as 2.55 lb (216 g without mouthpiece). Dimensions are about 18 cm long, 23 cm wide, 8 cm high.























