This particular Airsoft Surgeon Zombie Hunter is based on a WA M4 GBBR Inokatsu Series and are known for having one of the systems M4 blowback gas more realistic of the market.
It may seem just another M4 more, but once Airsoft Surgeon has been overcome and is far more superior than any other GBBR on the market.
Weight: 3,400 g
Length: 793 mm
Loader capacity: 50 rds
Power: 420 fps
Operation: Green Gas / Top Gas
Shooting mode: Semi/Auto
This model is based on the traditional M4 Inokatsu but clearly improved and modified (this video is only a high benchmark of one of Inokatsu GBB not the model).