The KWA E-14 bucking fits all electric KWA rifles, including the AEG and ERG series. Occasional replacement will help restore accuracy and prevent jamming. On respective diagrams, the bucking appears as KM4 AEG and RM4 part 159 and VM4 part 158.
This part fits all KWA AEGs, including the AEGs 2, 2.5, and 3.