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Specna Arms M4 AEG Rifle FLEX Series M4 URX SBR SA-F01

Specna Arms
SA-F01 Black



Specna Arms FLEX Series M4 URX SBR SA-F01 AEG Rifle

High Performance, Adaptability & Durability: The Specna Arms SA-F01 FLEX™ Carbine Replica brings a unique blend of superior performance and adaptability. Key feature includes the quick spring change system, ESA™, which enables efficient velocity adjustments for varying game conditions, without needing to remove the gearbox from the gun.

Quality Construction & Exceptional Balance: Featuring nylon-reinforced polymer construction for increased durability. The SA-F01 is fully compatible with LiPo and LiFe batteries and includes a factory-installed main spring offering a ~375 FPS muzzle velocity. Additionally, the package includes an M90 spring providing an optional ~300 FPS velocity. Its lightweight and balanced design makes it a go-to choice for dynamic CQB games.

Internal Setup: Housing steel gears, a polycarbonate plastic piston with a full steel strip, and a rotary Hop-Up chamber. The 6.03mm precision barrel is a noticeable upgrade from the standard 6.08mm barrels found in most AEGs. Seamless compatibility with M140 springs.


  • Quick spring change system, ESA™
  • Nylon-reinforced polymer components
  • Compatibility with LiPo and LiFe batteries
  • Included M90 spring for velocity adjustment
  • 6.03mm precision barrel
  • Lightweight and balanced


Overall Length 25.5" - 29" fully extended
Weight 4.7 lbs
Outer Barrel Length 8"
Barrel Thread 14mm CCW
Inner Barrel Length 229 mm
Inner Barrel Diameter 6.03 mm
Muzzle Velocity ~ 375 fps (default), ~ 300 fps (with M90 spring)
Fire Modes Safe/Semi/Full-Auto
Color Black or Half-Tan
Gearbox QD V2, 8mm bushings
Magazine Capacity 380rd hi-cap S-Mag
Package Includes Rifle, 380rd hi-cap mag, flip-up iron sights, additional M90 spring
Battery Combo Adds 7.4V 1100mAh 20C LiPo Nunchuck, B3+ LiPo Charger