T-N.T. Studio APS-X HOP-UP System H+ Retrofit Kit for GHK M4 GBB (320mm) Length-(mm)_280 PTS Griffin Armament M4SD Linear

PTS Griffin Armament M4SD Linear Compensator (CCW)

please check out the "RWC Milspec Size Stock Tube for Systema PTW"

This product is designed for Airsoft and is already blocked the gas pipe tunnel

2500 Rounds Loading Capacity Box Magazine

Salient Arms International (SAI)

T-N.T. Studio APS-X HOP-UP System H+ Retrofit Kit for GHK M4 GBB (320mm) Length-(mm)_280 PTS Griffin Armament M4SD LinearT N. T. Studio APS X HOP UP System H+ Retrofit Kit for GHK M4 GBB (320mm) Aluminum Construction Design For Upgrade the Origianl Parts The kit ensures better accuracy due to better and finer tuning of the hop up. Suitable For GHK M4 Series Airsoft Gas Blow Back GBB Rifle