Maxx Model CNC Aluminum Hopup Chamber for M4 / M16 Series Airsoft AEG Rifles (Model: M4P - PRO)

"Have an M4A in an AEG build and an M4P in an HPA Jack build and they are both great. Easy to install and make small adjustments.

"i haven't noticed a big difference in range but its cool to see the bbs, only con is i cant use speed mags anymore.