SHS High Speed Long Motor for Airsoft AEG M4/MP5/M16/P90/SR16 Suitable for airsoft AEG M4, M16, P90, MP5, SR16, and similar variants. Stator Magnet Material: Neodymium Motor Pinion: D-Shaped Compatibility: Most Version 2 or other gearboxes that require long motors. Ultra fast when combined with SHS High Speed Gears.