E&C 8mm Complete QD Transform M4 Gearbox Version 2 Rear Line."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 Ver.2 8mm M4 gearboxes. 2pcs 8mm ball bearings, 4pcs metal bushings. Replaces all major brand M4 standard gearbox. Version 2 gearbox with rear 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. - MP045 (Rear) Weight - Approx 496g Suitable for outdoor wargame activities.