KJ Works M9A1 CO2 FULL METAL GBB Pistol m4 Hop Up dial located inside

Hop Up dial located inside magazine chamber

Madbull RAS Fixed Rail

and 20 inch barrel models

The CO2 power is only designed for model: XM-PB4

KJ Works M9A1 CO2 FULL METAL GBB Pistol m4 Hop Up dial located insideKJ Works M9A1 CO2 FULL METAL GBB Pistol 1: 1 Ratio realistic gas blow back airsoft pistol FULL METAL SLIDE & BARREL ASSEMBLY Powerful CO2 offer 330 FPS out from the box Gas Blow Back Pistol with Semi Automatic Shooting Mode Extreme smooth slide cycling with clicks & clacks metal sound Strong recoil feel (better hold with both hands) Special type magazine accommodate one cartridge of CO2 tank 21+1 Rds Loading Capacity Magazine Also Compatible with Top