The Matrix G2 gearbox is the most advanced gearbox in its price point, offering a microswitch trigger, inline MOSFET, steel gears, aluminum cylinder, full steel teeth piston and an expanding cylinder head, providing the entry level Airsofter with high performance capability at a low cost. Magazine Capacity: 300rd Hi-Cap magazine included. Compatible with Matrix, Tokyo Marui and other similar M4 / M16 Series Airsoft AEG Magazines Thread Direction: 14mm Positive Gearbox: Ver 2 Full Metal, Fully Upgradeable / with Micro-Switch trigger / 7.4V / 11.1V Lipoly Ready (15~20C) Motor: Long Type / High torque Fire Modes: Semi/Full-Auto, Safety Package Includes: Gun, Magazine Battery (Not Included): 9.6v NiMh 1600mAh / 11.1v LiPo Butterfly Type recommended (Wired to buffer tube w/ a Small Tamiya connector) Hopup: Yes, Adjustable