SA M4 Keymod Gen2 (SA-F02 FLEX™ HAL ETU™) – Black

Specna Arms M4 Keymod Gen2 (SA-F02 FLEX™ HAL ETU™) in black finish is a high-performance airsoft rifle with 115 m/s power and upgraded internals. It features a HAL ETU™ processor unit with pre-cocking and trigger sensitivity adjustment. The nylon body and Keymod handguard ensure excellent handling, while the TDC hop-up chamber with Helium™ flat bucking delivers great accuracy.

183,96 € tax incl.

Availability: In Stock at store

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SPARMS397-BK

: Specna Arms

Accessories

  • 10,57 € In Stock

    : Wosport

    MAG022

    Ms2 MULTI-FUNCTION SLING tactical sling from WoSporT in black. For airsoft and real firearms, including duty use. 2-point sling with the option to switch to 1-point. MS2 sling replica in Magpul style. Heavy-duty steel carabiners with quick release and safety lock.

    10,57 €
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  • 9,26 € In Stock

    : BLS

    1KG-H25

    BLS PRECISION Airsoft Pellets weighing 0.25 g in a pure white finish. 1 kg package (resealable bag, 4000 BBs). The most popular ammunition for all airsoft guns (rifles, sniper rifles, LMGs, SMGs, shotguns, and pistols). Suitable for AEG, HPA, gas guns, and spring-powered replicas. The world’s best-selling BBs. Hand-measured quality control. BLS –...

    9,26 €
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  • 9,68 € In Stock

    : BLS

    1KG-H28

    BLS PRECISION Airsoft Pellets weighing 0.28 g in a pure white finish. 1 kg package (resealable bag, 3500 BBs). The most popular ammunition for all airsoft guns (rifles, sniper rifles, LMGs, SMGs, shotguns, and pistols). Suitable for AEG, HPA, gas guns, and spring-powered replicas. The world’s best-selling BBs. Hand-measured quality control. BLS –...

    9,68 €
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  • 10,57 € In Stock

    : FMA

    TB1261-BK

    QD Tactical Stubby Grip by FMA in black finish. For quick and secure attachment to RIS handguards using a QD lock. Lightweight and durable construction made from polymer. Non-slip grooves for better grip. The grip is hollow and features a screw-on cap for storing small items.

    10,57 €
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  • 9,73 € In Stock

    : Specna Arms

    SPARMS029-DE

    S-MAG Hi-Cap Magazine for AEG M4 / AR15 Rifles (MK18, HK416) by Specna Arms in Dark Earth. 380 BBs capacity. Reliable winding, perfect feeding, less frequent reloading. Durable polymer body with texture for a secure grip. Slim profile suitable even for tight pouches. Best choice for Specna Arms PRIME™ rifles and other series.

    9,73 €
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  • 9,30 € In Stock

    : Specna Arms

    SPARMS030-BK

    S-MAG Mid-Cap Magazine for AEG M4 / AR15 Rifles (MK18, HK416) by Specna Arms in black. 125 BBs capacity. Reliable feeding even at high RoF and with heavier BBs. Durable and lightweight polymer body with textured surface for a secure grip. Slim profile suitable even for tight pouches. Best choice for Specna Arms PRIME™ rifles and other series.

    9,30 €
    In Stock
  • 93,04 € In Stock

    : FMA

    TB1075-BK

    AN/PEQ15 LA5-C Ultra High Power airsoft version by FMA in black color. LED flashlight with functional IR covers. More powerful green and IR laser for use with NVG. Compact size and durable nylon body. Mounts on RIS rail for weapons like M4, MK18, AK, CZ EVO, and others. PEQ box adds tactical versatility without adding weight. Powered by 2 CR123A...

    93,04 €
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  • 16,92 € In Stock

    : Wosport

    WOSP77-BK

    Introducing the Lever Silence Speed Loader for 1000 BBs by WoSporT in a transparent (bright). No more refilling the loader after every magazine! Convenient loading of mid-cap magazines using a rotating lever! Thanks to the internal silicone insert, you won't rattle for miles! The loader fits M4/AR15 magazines. You can also purchase an adapter for...

    16,92 €
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  • 12,69 € In Stock

    : Wosport

    WOSP166-BK

    WoSporT quick-adjust 2-point sling FARAON in black finish is a universal weapon sling designed for fast handling. It allows an instant transition from secured carry to shooting position and features a rubberized pull tab for a firm grip. The design is based on proven Ferro Slingster-type slings with additional improvements for comfortable use.

    12,69 €
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  • 63,01 € In Stock

    : Vector Optics

    SCRD-41

    MAVERICK 1x22 Gen3 Red Dot Sight by Vector Optics in black (S-MIL). The best-selling airsoft red dot sight. 3 MOA dot for fast aiming. 11 brightness levels of red illumination. Side-loading battery tray for replacement without losing zero. Rubber-armored body for scratch resistance. Optical center height 41 mm. Includes a killflash to prevent lens...

    63,01 €
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  • 28,33 € In Stock

    : TITAN

    TIT027

    TITAN 11.1V 1000 mAh Li-Po Battery with a discharge rate of 25C in Stick (buffer) configuration. Dimensions: 105 x 19 x 17 mm. Connector: T-Dean. Excellent performance, rate of fire, longer battery life and better trigger response. Ideal for AEG assault rifles, LMG, SMG / PDW and DMR weapons. Charge only with high-quality, powerful chargers. Don’t...

    28,33 €
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  • 168,74 € In Stock
    Free shipping

    : Specna Arms

    SPARMS274-BK

    Specna Arms EDGE™ set of Maverick-IV red dot sight and 3x magnifier in black. Accuracy and reliability in a value package. Quick attachment with QD mount on a RIS rail. Excellent combo offering the option for close-range (CQB) and medium-range shooting with a 3x flip-to-side magnifier. Suitable for AEG, GBB, and HPA guns. Magnifier is also suitable...

    168,74 €
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  • 105,30 € In Stock

    : Vector Optics

    OPSL40

    C1 4x32 Prism Scope by VictOptics in black. Lightweight and compact optic with 4x magnification. BDC reticle for .223 / 5.56 caliber, 750 G shockproof. Rubber-armored body for increased protection. Top plate for mounting red dot (TEK / MOJ / MGT footprint). Red and green illumination (5 levels each). IPX4 water resistance. Nitrogen purged to...

    105,30 €
    On the way
  • 52,86 € In Stock

    : Gens ACE

    GEA60WE1

    G-TECH iMars Mini Charger by Gens ACE in black. Set includes power adapter and USB-C cable. Up to 60 W charging power. Supports smart G-TECH batteries. Designed for Li-Po, Li-Ion, LiFe (2-4S) and NiMH batteries (2-12S). Suitable for FPV drones, airsoft, and RC models. Powered via USB-C (PD, QC, etc.). XT60 and T-Dean adapters included. 

    52,86 €
    In Stock
  • 21,15 € In Stock

    : Gens ACE

    GEA10003S25D

    LiPo Battery 11.1V - 1000 mAh (25C) by Gens ACE in Buffer stick configuration. Dimensions of 103 x 18 x 16 mm. T-Dean connector. High-performance 11.1V LiPo battery with 25C discharge rate. Increases rate of fire and improves motor response. Suitable for AEG rifles, machine guns, SMG/PDW, and DMR platforms. Use only with quality high-performance...

    21,15 €
    In Stock
  • 41,87 € In Stock

    : TITAN

    TIT032

    TITAN DIGITAL CHARGER V2 for Li-Po and Li-Ion batteries. V2 with USB-C charging and EU power adapter. 20% higher performance. Compact metal charger with a clearer digital display. Also works as a battery tester directly in the field. High safety thanks to a cell-by-cell balancing system. Supports 2S and 3S batteries (7.4V - 11.1V).

    41,87 €
    In Stock
  • 109,53 € In Stock

    : NOVRITSCH

    NOVRITSCH258

    Novritsch Flare Smoky BT Tracer & Chrono in black combines BBs illumination, smoke effect, muzzle flash simulation and Bluetooth chrono in one device easily controlled via the ESHOOTER app. It offers 8 modes and features a CNC-machined aluminum body with VG & PG 50/50 liquid leak certification. Dimensions are 126 × 38 mm.

    109,53 €
    In Stock
  • 84,16 € In Stock

    : Specna Arms

    SPARMS398-BK

    Specna Arms transport bag URBAN WAR in black finish is a durable bag for safe transport of firearms and airsoft rifles up to 87 cm. It offers space for 2 long guns, practical accessory pockets and backpack carry option. Made from Cordura 1000D and durable nylon with padding to protect your gear during transport. The bag features MOLLE webbing and a VELCRO...

    84,16 €
    In Stock

Why Choose M4 Keymod FLEX™ Gen2 from Specna Arms?

Specna Arms M4 Keymod Gen2 (SA-F02 FLEX™ HAL ETU™) is built on a lightweight yet durable FLEX™ series nylon body reinforced with glass fiber, offering a realistic matte finish and high durability, outperforming cheaper alloy bodies. The outer barrel with a 14 mm CCW thread and steel components such as pins, screws, and the ejection port provide strength where needed. The result is a lightweight yet robust assault rifle platform ideal for CQB environments and dynamic gameplay. The AR15 (M4) platform offers intuitive controls, including an ambidextrous charging handle, clear fire selector, and easy hop-up adjustment via the ejection port. The Keymod handguard allows mounting accessories such as a foregrip, tactical flashlight, or PEQ box. The spacious Crane Stock with QD sling points ensures a stable shooting platform. The battery is stored in the stock, allowing the use of buffer stick, nunchuk, or crane batteries. Overall, this rifle combines low weight, modern construction, and high-quality Gen2 internals. The FLEX™ Gen2 series includes features such as the Æther™ gearbox with HAL ETU™, metal nozzle, TDC hop-up chamber with Helium™ flat bucking, and a 6.03 mm precision inner barrel.

Key Features of Specna Arms M4 Keymod FLEX™ Gen2

HAL ETU™ Processor Unit

Advanced features such as binary trigger, pre-cocking, trigger sensitivity adjustment, and protection for Li-Pol batteries.

Lightweight FLEX™ Construction

Glass fiber reinforced nylon body for low weight and high durability.

6.03 mm Barrel, TDC Hop-up & Helium™ Bucking

Improved accuracy and consistent trajectory thanks to the TDC hop-up system.

ESA™ QSC System & Æther™ Gearbox

Quick spring change ESA™ without disassembly. Reinforced Æther™ gearbox with 8 mm bearings.

Keymod Handguard

Easy mounting of accessories like Keymod grips, RIS rails, flashlights, or PEQ box.

HAL ETU™ Programming

Overview of HAL ETU™ settings and functions.

Technical Specifications

  • Platform: M4 / AR-15
  • Series: FLEX™ Gen2
  • Length: 790-875 mm
  • Weight: 2340 g
  • Power Source: AEG
  • Unit: HAL ETU™
  • Gearbox: Æther™ V2 QSC
  • Quick Spring Change: Yes (ESA™)
  • Hop-up: TDC
  • Inner Barrel: 6.03 mm
  • Velocity: 115 m/s
  • Bearings: 8 mm
  • Connector: T-Dean
  • Body Material: Fiber-reinforced nylon
  • Handguard: Keymod
  • Thread: 14 mm CCW

Package Contents

  • Specna Arms M4 Keymod FLEX™ Gen2
  • Hi-cap magazine (300 BBs)
  • Flip-up sights
  • M90 spring
  • Specna Arms stickers
  • User manual

Important Setup Instructions

To use the rifle, you must activate the HAL ETU unit by following these steps, otherwise the gun will not respond:

  1. Set the fire selector to Safe
  2. Connect the battery and wait 3 seconds until you hear a beep
  3. Pull and hold the trigger for 5 seconds until another beep is heard
  4. The rifle is now ready to use
VariantsFLEX™ Gen2
ColorBlack
Muzzle velocity (m/s)115 (m/s)
Recommended weight of ammunition0,25g - 0,28g
Thread (mm)14- (mm)
Outer length MINIMAL (mm)795 (mm)
Outer length MAXIMAL (mm)875 (mm)
Inner barrel length (mm)365 (mm)
Weight (g)2345 (g)
Body/receiver materialABS / Plastic
Mounting SystemKeyMod
Gearbox versionV2 - ESA™
Amount of piston teeth14
Bearings (mm)8 (mm)
Bearings (material)Metal
Piston headPlastic
NozzleMetal
Spring guidePlastic
Hop-Up chamber materialPlastic
Battery typeBuffer stick
Connector typeT-Dean
Magazine materialPlastic
High-cap / Mid-capHigh-cap
Magazine capacity300
Processor unitYES
BlowbackNO
Battery includedNO
Battery ChargerNO
Weapon accessoriesYes