Adjustable hop-up unit Adjustable rear sight Full length top rail Functional charging handle Quick Change Spring Option Fully Licensed Heckler & Koch trademarks, licensed by Umarex Easy field stripping/ disassembly Easy access battery compartment Folding skeleton stock w/ rubber butt pad Integrated forward and rear sling mounts Ambidextrous selector switch In the Box HK UMP AEG Hi-cap Magazine (400rd) 8.4v Stick Type Battery Standard Wall Charger Manual Specifications: Operation Electric AutomaticBuild/Body Ultra durable fiber polymer body with full metal internalsFiring Modes Semi-automatic and Full-automaticGearbox Full metal Version 3, w/ Easy Access Quick Spring Change Feature California Proposition 65 Warning: Cancer and Reproductive Harm - www.P65Warnings.ca.gov