Apeks Regulators — Precision Breathing Equipment for Every Diver
Apeks has been engineering some of the most trusted regulators in scuba diving since the early 1970s. Founded in Blackburn, Lancashire, England by Ken Ainscough and Eric Partington — whose initials form the name "Apeks" — the company began in a small garage and grew into a globally recognized manufacturer of high-performance dive equipment. Today, still designed and built in Blackburn, Apeks is part of the Aqua Lung Group and produces around 300 regulators per day entirely in-house. Their credentials speak for themselves: Apeks was the first dive brand in the world to achieve and then exceed the EN250A cold water safety standard, and holds Norsok Standard U-101 accreditation, a demanding benchmark originally developed for commercial divers in the petroleum industry.
At DiveCatalog.com, we carry the full current Apeks regulator lineup — complete first-and-second-stage sets, individual first stages, second stages, octopuses, and specialty configurations including sidemount and technical diving rigs. Whether you're completing your Open Water certification and looking for a first regulator that will grow with you, or you're building out a twin-set technical rig, you'll find what you need here.
The Apeks range spans several distinct families. The AT and ATX series offer balanced performance at an accessible price point for warm-water recreational divers. The XTX40 and XTX50 represent the core of the recreational and advanced recreational lineup, built around Apeks' over-balanced diaphragm first stage technology. The XL4 OCEA breaks new ground with eco-conscious construction — recycled materials, bio-plastics, and a partnership with Plastic Bank — without compromising on underwater performance. At the top end, the MTX-R and MTX-RC are cold-water-optimized, freeze-resistant regulators that trace their lineage to testing conducted with the United States Navy Experimental Dive Unit.
This collection is organized to help you find the right fit — whether that's a complete set, individual component upgrades, or a matched octopus for an existing Apeks first stage.
Who Are Apeks Regulators For?
| Diver Type |
Recommended Series |
Why It Fits |
| New & recreational divers |
AT, ATX |
Fully balanced, warm-water optimized, straightforward to use, accessible price |
| Intermediate & advanced recreational |
XTX40, XTX50 |
Over-balanced diaphragm first stage, cold water rated, nitrox compatible to 40% |
| Eco-conscious divers |
XL4 OCEA |
Built from post-consumer recycled polymers and bio-plastics; ocean plastic-negative |
| Cold-water divers |
XTX50, MTX-R, MTX-RC, XL4+ |
Environmentally sealed first stages, rated for use below 10°C / 50°F |
| Technical & cave divers |
MTX-RC, TEK3, Sidemount Sets |
High port count, DIN configuration, adjustable breathing effort, sidemount-optimized |
| Military & professional |
MTX-RC Single Cylinder Set |
Military-grade engineering, NEDU-tested cold water lineage, extreme environment reliability |
Popular Apeks Regulator Models
Apeks XTX50 — The Benchmark Recreational Regulator
The XTX50 is the heart of the Apeks lineup and one of the most respected regulators at its price point. It uses the DST first stage — an over-balanced diaphragm design in which medium pressure to the second stage increases faster than ambient pressure as you descend, meaning it actually breathes easier the deeper you go. Four medium-pressure ports are mounted on a rotating turret for flexible hose routing, and an environmental dry system keeps water away from the main spring chamber, preventing ice formation in cold conditions. The pneumatically balanced second stage delivers effortless airflow, and the Diver Changeable Exhaust (DCE) system lets you swap between a compact exhaust tee and a wider one that diverts bubbles — useful for photographers. Nitrox-compatible to 40% out of the box. Available in DIN and Yoke.
Apeks MTX-RC — Cold Water and Technical Performance
The MTX-RC is built for divers who push into demanding environments. Its lineage traces back to the original MTX, which was developed in accordance with the US Navy Experimental Dive Unit extreme cold water test. The first stage features a satin-plated brass body with heat-exchanging ribs, an over-moulded end cap and environmental diaphragm designed to prevent ice build-up that could trigger a free-flow, and a ribbed diaphragm clamp for improved thermal performance. Five medium-pressure ports (four on a rotating turret) and two angled high-pressure ports give technical and sidemount divers plenty of routing flexibility. The second stage adds an oversized breathing effort adjuster — operable with gloves — plus the same DCE exhaust system found across the XTX range. EN250A certified for cold water use to 60 metres. Available in DIN and Yoke.
Apeks XL4 OCEA — Performance with Environmental Purpose
The OCEA is the first scuba regulator of its kind: built from recycled materials and bio-plastics, manufactured in Apeks' solar-powered Blackburn facility. The black components use polymers made from up to 70% post-consumer recycled waste; the coloured parts use bio-based polymers derived from non-petroleum sources; the brass is lead-free and more recyclable than standard alloys. Beyond materials, each OCEA sold funds the collection of 5kg of upstream plastic waste through a partnership with Plastic Bank, making it the world's first ocean plastic-negative regulator. The performance underneath that eco story is genuinely solid — it uses the DS4 first stage platform with the same over-balanced diaphragm design as the XTX series, and the XL4+ second stage is compact and lightweight to reduce jaw fatigue on longer dives. Available in Yucca and Black/Grey, in DIN and Yoke.
Apeks MTX-R — Expedition-Ready Technical Regulator
The MTX-R is the foundation of the MTX range and is built around a forged first stage body with heat-exchanging ribs for maximum thermal output in cold environments. An innovative over-moulded end cap and environmental diaphragm help prevent ice build-up around the diaphragm in near-freezing water. The second stage is high-performance and pneumatically balanced, with large protective elastomer bumpers — a practical detail for technical divers managing multiple second stages. Available in DIN and Yoke, with matched octopus and MTX-R Sidemount Set also available.
Apeks XTX40 — Capable Entry into the XTX Family
The XTX40 shares Apeks' over-balanced diaphragm technology and is available with either the DS4 first stage (fixed port positions) or the DST first stage (swivel turret). Cold water rated, nitrox compatible to 40% out of the box, and available in both DIN and Yoke. The XTX40 DIN with Nitrox DS4 version is pre-cleaned for high-percentage oxygen use. A solid step up from the AT/ATX series for divers who want the XTX breathing experience at a more accessible price.
Apeks AT / ATX — The Smart First Regulator
The AT and ATX are Apeks' entry-level Yoke regulators, designed for warm-water recreational diving. Both feature a fully balanced first stage — a meaningful distinction from truly budget regulators — paired with a balanced second stage. If you're buying your first regulator and plan to dive tropical destinations primarily, these deliver genuine Apeks build quality without the premium price of the XTX series.
How to Choose the Right Apeks Regulator
Balanced vs. Over-Balanced First Stages
All Apeks regulators use at minimum a balanced first stage, meaning breathing effort stays consistent as your tank pressure drops. The XTX40, XTX50, XL4 OCEA, MTX-R, and MTX-RC all use Apeks' signature over-balanced diaphragm design, which goes a step further — delivering more airflow as you descend. This is a real-world performance advantage at depth or in current.
Diaphragm First Stages and Cold Water
Apeks builds across their range with diaphragm first stage designs, which isolate the internal mechanism from the water. This matters most in cold, silty, or saltwater-heavy environments. The environmental dry system found on the XTX50 and above adds another layer by keeping the spring chamber dry, preventing ice formation that could cause a free-flow.
DIN vs. Yoke
Most Apeks regulators are available in both configurations. DIN screws directly into the cylinder valve and is the standard for technical diving and in most European operations. Yoke (A-clamp) is the North American standard and more widely available at rental shops and dive resorts. If you're unsure, Yoke is the safer default for recreational divers. Most Yoke models can be adapted for DIN use later with the appropriate insert.
Cold Water Performance
For diving regularly below 10°C / 50°F, the MTX-R and MTX-RC are the clear choices — both were developed with extreme cold conditions as the primary design target. The XTX50 and XL4+ also carry cold water ratings. The AT and ATX are warm-water optimized and not recommended for cold-water environments.
Sidemount and Technical Configurations
Apeks offers purpose-built sidemount sets based on the XTX50 and MTX-R platforms, pre-configured with matched hose lengths for sidemount harnesses. The TEK3 set is built for technical back-gas configurations with multiple ports oriented for stage and decompression bottle use.
Nitrox Compatibility
Most Apeks regulators are compatible with enriched air nitrox to 40% straight out of the box. The XTX40 DIN with Nitrox DS4 first stage is pre-cleaned for high-percentage oxygen use. For oxygen percentages above 40%, contact us to confirm the appropriate configuration and servicing requirements.
Why Buy Apeks Regulators from DiveCatalog.com?
DiveCatalog.com is an authorized Apeks dealer. Every regulator we sell is genuine, covered by the full manufacturer warranty, and backed by Apeks' authorized service network.
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Authorized dealer — genuine Apeks products, not gray market
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Full manufacturer warranty — covered on every new regulator
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Expert staff — our team are working divers who use this equipment
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Fast shipping — most in-stock items ship within one business day
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Financing available — spread the cost of higher-end technical gear
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Rewards program — earn points on every purchase
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Easy returns — straightforward return process if something isn't right
We also carry a curated selection of used and open-box Apeks regulators at reduced prices — all inspected and accurately described.
Frequently Asked Questions — Apeks Regulators
What is the best Apeks regulator for recreational diving?
The XTX50 is the most popular choice for recreational and advanced recreational divers who want a feature-rich regulator that will grow with them. The XTX40 offers the same over-balanced diaphragm technology at a slightly lower price. For new divers focused on warm-water destinations, the ATX delivers solid Apeks quality at a friendlier entry point.
Are Apeks regulators good for cold water?
Cold water is Apeks' heritage. The MTX-RC and MTX-R are specifically engineered for near-freezing conditions, with designs traceable to US Navy Experimental Dive Unit testing. The XTX50 and XL4+ are also cold water rated (below 10°C / 50°F). The AT and ATX are warm-water optimized and not the right choice for cold conditions.
What is the difference between the XTX40 and XTX50?
Both use Apeks' over-balanced diaphragm technology, but the XTX50 adds a breathing resistance control knob on the second stage alongside the venturi lever, giving divers finer control over breathing effort. The XTX50's DST first stage also has a swivel turret as standard. In practice, the XTX50 is the better fit for demanding conditions; the XTX40 is a sound, capable choice for recreational diving.
What does the "MTX" stand for in the MTX-RC?
MTX refers to the original military-inspired MTX regulator that formed the foundation of this product family. The RC designation indicates the addition of user-adjustable breathing controls on the second stage compared to the standard MTX-R, giving divers the ability to tune performance for different environments.
Can I use an Apeks regulator with Nitrox?
Most Apeks regulators are compatible with enriched air nitrox to 40% O2 out of the box. The XTX40 DIN with DS4 first stage is pre-cleaned for high-percentage oxygen use. For percentages above 40%, speak with us or an authorized Apeks service technician about the appropriate configuration.
What is the difference between DIN and Yoke on Apeks regulators?
DIN screws directly into the cylinder valve and is rated to higher pressures — it's the standard for technical diving and widely used in Europe. Yoke clamps over the valve and is the common North American standard, making it easier to use at most dive resorts and rental operations. Most Apeks regulators are available in both. If you're unsure which suits your diving, contact us and we can advise based on where and how you dive.
How often should I service my Apeks regulator?
Apeks recommends annual servicing or after every 100 dives, whichever comes first. Regular servicing keeps the regulator breathing correctly, maintains safety, and is required to preserve the warranty. We can point you toward authorized Apeks service centers.
What makes the Apeks XL4 OCEA different from other regulators?
The OCEA is built using post-consumer recycled polymers (up to 70% recycled content in the black components), bio-based plastics derived from non-petroleum sources, lead-free eco brass, and trivalent chrome plating that uses fewer harmful chemicals. It is manufactured in Apeks' solar-powered Blackburn facility and is certified ocean plastic-negative through a partnership with Plastic Bank — each sale funds the recovery of 5kg of plastic waste. Performance is not compromised: it uses the same DS4 over-balanced first stage platform as the XTX series.
Is the Apeks Sidemount Set ready to dive out of the box?
Yes. Both the XTX50-based Sidemount Set and the MTX-R Sidemount Set come pre-configured with matched hose lengths suited to sidemount harness use. They pair well with Apeks' own sidemount BCD range.
Do Apeks regulators come with a warranty?
Yes. Apeks provides a manufacturer warranty on all new regulators purchased through authorized dealers. Buying from DiveCatalog.com ensures your warranty is valid and that you have access to the Apeks authorized service network.
Can I mix Apeks first and second stages?
Generally yes — Apeks uses standard medium-pressure port configurations that are compatible across the range. The octopus second stages sold individually are designed to pair with Apeks first stages. If you have a specific mixed configuration in mind, contact us and we'll confirm compatibility.
Where are Apeks regulators made?
Apeks regulators are designed and manufactured at their facility in Blackburn, Lancashire, England. All components are produced in-house, and the facility runs on solar power. Apeks is part of the Aqua Lung Group.
Whether you're gearing up for your first dive trip or you're an experienced diver ready to upgrade to a regulator that performs without compromise, DiveCatalog.com has the right Apeks model for you. Browse the collection above, and reach out to our team if you'd like a recommendation matched to your diving style and conditions.
