Updated for 2023 with a 2nd stage heat exchanger, the Apeks XL4+ is a compact, lightweight regulator suitable for diving in all environments including cold water locations. Its design and low weight help reduce jaw fatigue on long dives. The XL4+ also makes an ideal stage regulator, perfect for the exploration diver with a large amount of equipment.
The XL4+ regulator is a high-performance option for those technical divers serious about weight savings.
Features:
1st Stage
- Compact machined first stage based on the expedition tested Apeks DS4 platform.
- Break through, innovative over-moulded first-stage endcap and environmental diaphragm helps prevent ice build-up that can cause first stage free flow in extreme circumstances. Also protects the first stage from impact damage.
- Large surface area heat exchanger diaphragm clamp helps increase the gas temperature inside the first stage, resulting in improved cold water performance.
- Unique over-balanced diaphragm design – as the diver descends, the over-balancing feature allows the medium pressure gas in the hose to increase at a faster rate than ambient. This results in superior performance at depth.
2nd Stage
- Compact and lightweight second stage improves comfort and helps reduce jaw fatigue on long duration dives.
- High performance pneumatically balanced lever operated poppet valve.
- Large, over moulded self-flushing and controllable purge button.
- Ergonomic Venturi lever is easy to use and locate.
- Flexible nylon braided hose has better cold water performance than a traditional rubber hose.
- Standard metallic hose connection for interchangeability.
- Comfo-bite mouthpiece has a unique bridge that fits across the upper palate and does not require bite pressure to stay in place.
- Re-useable mouthpiece clip makes it simple to change mouthpieces in the field.
- Durable and flexible rubber exhaust tee provides excellent bubble diversion.
- UV inhibitors to help prevent discoloration of the white materials.
Specs:
| Connections | Yoke / INT |
| Type of first stage | Over-balanced diaphragm design, environmentally sealed |
| Body Type | One-piece forged body |
| Number of HP ports | 2ʺ(7/16″ UNF) |
| Number of MP ports | 4 (3/8″ UNF) |
| Weight | 1041g (2.3 lb) |
| Environmental Dry Kit | Standard |
| First stage exterior | Satin |
| Coldwater Use | Yes |
| Type of second stage | Pneumatically balanced |
| Opening Effort Control Knob | No |
| Integrated Venturi Lever | Yes |
| Mouthpiece | Comfo-bite™ |
| Exhaust tee | Standard, one set |
| Heat Exchanger for freezing resistance | Yes |
| Hose type | Braided Flexi-hose |
| Overall work of breathing (WOB) scores | Avg. 0.90 joules/liter |
| Nitrox compatible | Yes to 40% O2 when new, out of the box / Can be O2 cleaned to 100%. |