Our expert's opinion
"I find that this SA-F04-RL FLEX Gen.2 replica is a very solid choice for players who want a compact, modern design that comes well-equipped right out of the box. I particularly appreciate the built-in brushless motor, the simple MOSFET programming, and the ambidextrous controls, which make it truly comfortable to use in both CQB and outdoor settings. The Light Ops stock and quick-change spring further enhance its appeal for those looking for a versatile and high-performance replica right out of the box."
Charly
Product Manager
Description
The SA-F04-RL FLEX Gen.2 BLDC HAL ETU SPECNA ARMS AEG replica, a complete, ready-to-play M4 platform
The SA-F04-RL FLEX Gen.2 BLDC HAL ETU is an M4-style AEG replica / AR-15 replica from SPECNA ARMS, designed for players looking for a replica that comes standard with a brushless motor, an advanced MOSFET, and a patented gearbox. Available in three finishes (black, half-tan, olive green), it combines a nylon-fiber-reinforced polymer body with a selection of metal parts at the most heavily stressed contact points. Its adjustable length from 670 to 755 mm makes it truly versatile, whether in CQB or on wooded outdoor terrain.
An Æther Gen.2 gearbox and a HAL ETU MOSFET at the heart of the system
The Æther Gen.2 gearbox forms the mechanical foundation of this replica. Patented, it stands out for its reinforced frame, inspection windows, and integrated trigger adjustment system. It incorporates the ESA system, which allows for quick, tool-free spring changes. It accommodates springs up to M140, providing significant room for upgrading without needing to replace the gearbox. The gears are CNC-machined from steel, the piston is made of polycarbonate with integral steel vanes, and the slide bearings measure 8 mm. The aluminum nozzle is leak-proof.
The HAL ETU MOSFET uses a Hall-effect magnetic sensor to detect trigger pull, which eliminates physical contact and improves the trigger’s durability. It is programmed directly via the trigger, without any external tools or cables. It offers seven configurable firing modes: semi-auto, full-auto, 3-round burst, 5-round burst, binary mode, AUG mode, and sniper mode. Trigger sensitivity is adjustable across 5 levels (from 20% to 100%), and pre-cocking across 6 levels. It also features an active muzzle brake and a low-battery alarm.
The Dark Matter 27K brushless motor and Magnus TDC chamber come standard
The Dark Matter 27K High Speed brushless motor comes standard with the SA-F04-RL FLEX Gen.2, with no additional options required. Compatible with the HAL ETU, it offers faster acceleration than a comparable reference brush motor, while generating less heat during extended sessions. The battery connector is T-Dean; with the included T-Dean to Mini-Tamiya adapter, this replica is compatible with 7.4V and 11.1V LiPo batteries.
The hop-up chamber is a TDC Magnus (Top Down Center) type. It is adjusted from the top of the barrel via a central shaft, allowing for precise and repeatable adjustment from one session to the next. It is equipped with a Helium Flat Hop gasket. The precision steel barrel has an internal diameter of 6.03 mm. The outer barrel is threaded 14 mm counterclockwise (CCW), allowing a suppressor or tracer to be mounted directly onto it.
Construction, Ergonomics, and Accessory Compatibility
The body of the SA-F04-RL FLEX Gen.2 is made of nylon-fiber-reinforced polymer, with a matte finish and a scratch-resistant nano-coating. Metal parts cover the most exposed areas: flash hider, outer barrel, slide, fire selector, top cover release button, pins, and reload lever. The mode selector and magazine release are ambidextrous. The bolt catch is functional, and both the rear sight and front sight are foldable.
The handguard features the standard M-LOK on its sides and a Picatinny rail along the top, allowing for the secure mounting of scopes, flashlights, and accessories. The Light Ops stock is length-adjustable (6 positions) and features a rubber buttpad. The replica is compatible with M4-style mid-cap magazines. An additional M90 spring is included in the box to allow for use indoors or in CQB environments subject to strict power restrictions.
Important Information Regarding the SA-F04-RL FLEX Gen.2 BLDC HAL ETU SPECNA ARMS AEG Replica
The first time you use the replica, after connecting the battery, you will hear the HAL ETU™ system beep.
After hearing this, hold the trigger in SAFE mode for about 5 to 10 seconds to activate the module and begin using your replica.
Frequently asked questions (FAQ)
- What items are included with the SA-F04-RL FLEX Gen.2 BLDC HAL ETU SPECNA ARMS AEG replica?
This model comes with two S-Mag mid-cap magazines, each with a capacity of 125 BBs, and an additional M90 spring. The box also includes a T-Dean/Mini-Tamiya adapter, a speedloader, and a cleaning rod.
- What battery is recommended for this model, and what type of connector does it have?
The replica is equipped with a T-Dean connector and is compatible with 7.4V and 11.1V LiPo batteries. An adapter is included for use with batteries featuring a Mini-Tamiya connector, if necessary.
- What features does the built-in HAL ETU MOSFET offer?
The HAL ETU MOSFET uses a magnetic sensor to offer various firing modes, such as single shot, 3- or 5-round burst, and sniper mode. It also allows you to adjust the trigger sensitivity across 5 levels and configure pre-cocking for instant responsiveness.
- Is it easy to change the spring on this replica?
Yes, thanks to the patented ESA (Easy Spring Access) system, you can change the spring quickly without needing complex tools or removing the gearbox. This allows you to adjust the replica?s power to match your playing field?s rules in just a few moments.
- What are the advantages of the Dark Matter 27K brushless motor that comes standard?
This brushless motor offers high rotational speed and excellent energy management, which reduces heat buildup and increases responsiveness compared to a brushed motor. Its design, free of mechanical friction, extends its service life while optimizing the rate of fire.
- How does the hop-up adjustment work on this model?
The replica uses a TDC Magnus (Top Down Center) rotating chamber that applies perfectly vertical pressure to the Helium Flat Hop gas seal. This patented system ensures highly precise adjustment and increased shooting stability.
- What types of accessories can be mounted on the handguard?
The handguard is equipped with M-LOK mounts on the sides and underside, as well as a Picatinny rail on top for optics. The outer barrel features a 14 mm counterclockwise (CCW) thread for attaching a suppressor or tracer.
- Is this replica suitable for left-handed players?
Yes, the SA-F04-RL FLEX Gen.2 BLDC HAL ETU SPECNA ARMS AEG replica features ambidextrous controls, including the fire selector and magazine release. The Light Ops stock is also designed to provide optimal comfort for all types of shoulder positions.
Product content
1 x SA-F04-RL FLEX Gen.2 BLDC HAL ETU SPECNA ARMS AEG Replica
2 x S-Mag 125-bbs mid-cap magazines
1 x M90 Additional Spring
1 x T-Dean to mini-Tamiya adapter
1 x Speedloader
1 x Cleaning rod / unclogging rod
Features
- Replicas
- Caliber
- Propulsion
- Connections
- Shooting mode
- Energy
- Speed
- Length
- Minimum Length
- Internal barrel diameter
- No screws
- Integrated tactical rail
- Charger
- How it works
- Quick spring change
- Engine
- Gearbox Version
- Integrated mosfet
- Gears
- Body
- Brand
