"QD Transform" gearbox is a new generation gearbox with all the unique & great features of a STAR / ARES (QR gearbox) and Deepfire gearbox (Micro switch). This gearbox has an unique shell, spring guide, selector plate, cut-off lever and trigger, all other parts are compatible with regular AEG Version 2 8mm M4 gearboxes. 6pcs 8mm ball bearings. Metal air nozzles & Steel cylinder. Replaces all major brand M4 standard gearbox. Version 2 gearbox with front wire. Easy power upgrade system. Quick release spring and spring guide for easy power adjustment / spring replacement. Micro switch operation for shorter & better electric range. Faster trigger response design. Featuring "spring release" function. Full metal reinforced chassis / gearbox with metal gear set. Transformer gearbox will work with most AEG M4 Platforms (Modification may be required) E&C model no. - MP049A (Front) Weight - Approx 570g Original Packing NOTE: Self-installation required.