The G&G Combat Machine R16 Carbine AEG is an excellent, high quality AEG that is both affordable and upgradable. Built from G&G's extremely durable nylon fiber reinforced polymer, the externals of this AEG are both lightweight and durable and in some cases better than some full-metal body AEGs that use brittle, heavy potmetal. This AEG is designed to be a 1:1 scale replica to a classic M4A1 rifle. With a classic, adjustable multi-positional LE stock and clamshell style handguard that holds the batteries for this front-wired AEG, is an excellent all-around AEG for both field and indoor play. Internally tuned to fire approximately 340 FPS with 0.20g BBs. G&G's highly upgradable version 2 gearbox is TM-parts compatible. A removable carry handle and rear sight is adjustable for windage. When removed, a picatinny/weaver rail is exposed which other aftermarket optics such as scopes or red-dots can be attached as well.