Features:
      Full Metal Real Steel M4/M16-style Receiver Construction for Airsoft use (World Patent Pending)
-        Quick Inter-changeable Upper Receiver
-        Quick Change Power Module (300/400/450 fps)
-        100% Compatible with MARUI Hop-up & Inner Barrel design
-        Compatible with most MARUI Type-2 Gearbox Components (Incl. gear sets, motors, etc.)
-        WE Spring Release System (World Patented)
-        Super Low Power Consumption design
Infornmation:
Model: M4 RIS
Materials: Steel, Zine Alloy, Nylon, Rubber
Length: 780/860mm
Weight:3100g ( 7 pounds)
Power Source: AEG
Action: Semi/Auto
Ammo Type: 6mm airsoft BBs
Ammo Capacity: 300 round magazine
FPS: 400
Bunker Tech Upgrades
Maple leaf gbb 6.02mm Inner Barrel
Maple leaf  High Accuracy Hop-up Bucking- Internal Parts Adjust
All function checks, to avoid common tolerance issues.
BB weight for optimal performance: 0.36 gram