Premium Edition of the PTS Mega Arm MKM GBB-R in Dark Earth is available at Landwarrior Airsoft for £494.99... "PTS® Mega Arms MKM GBBR series of guns are variation based on the MA/AR15 platform. The Mega Arms GBBR (Airsoft Gas Blowback Rifle) represents the continued evolution of Airsoft guns as training systems.