MAXX CNC Aluminum Hopup Chamber M4i - PRO Gas Pistols A great and economical upgrade

A great and economical upgrade for G17 pistols

Innovative Hop-Up Thumb Dial located inside the gun (can see after dissemble the slide)

or sometime after

Integrated custom Storm regulator

MAXX CNC Aluminum Hopup Chamber M4i - PRO Gas Pistols A great and economical upgradeCNC Aluminum Hopup Chamber M4i Pro (with BB Latching System) unit is precisely machined to perform accurately and consistently on ICS CXP CS4 EBB (include old models) M4 M16 AEG series. The Hopup Chamber M4i unit is built with an aluminum Rotary Dial Knob for fine hopup adjustments, the precision Hopup Lever and 4mm Bucking Nubs (6mm Bucking Nubs are optional) to perform best with R Hop and Standard Hop to keep the BB shooting accurately and