T-N.T. Studio APS-X HOP-UP System H+ Retrofit Kit for GHK M4 GBB (320mm)

T-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