Planet Eclipse GTek 160R Black Red External Marker Upgrades King Arms Full Metal Blow ECHO1STAG15COM King Arms Full Metal Blow Back SIG 556 Shorty Airsoft Gun ( Licensed by Cybergun Battery & Charger Pkg ) is the one of the best officially licensed blowback SIGs available High strength reinforced polymer construction And the stretched pitch of the foregrip and frame make it a super stable platform that feels incredibly natural in the hands with plenty of room between the foregrip and trigger guard the AT Pipe allows Air Transfer from the ASA on the bottom of the frame into the foregrip mounted SL4 Inline Regulator without the need for hoses or fittings