This gearbox is identical to the original gearbox that comes standard in a M4A1 Gen 9 although the shell is made of nylon which gives needed strength if you're looking to mod in the future.
- M4A1 Gen 9
- ACR J10
*Your blaster may be compatible even though it isn't listed please send us a message if you're unsure.
- Gen 9 Gearbox