A review by Airsoft Outlet Northwest of the KWA RM4A1 ERG which is available right now at their online store... "The KWA RM4A1 ERG is an AR style, Electric Recoil Gun [ERG] that utilizes the patented Kinetic Feedback System [KFS]. This gives the user felt recoil with every trigger pull. All ERG Series rifles feature a mechanical/electrical cut-off system that works in conjunction with the ERG magazines to feed every BB and stop firing when the magazine is empty.

Highlighted features of the RM4A1 ERG are metal alloy receivers, MilSpec buffer tube and stock, a flat top rail, which allows operators to customize their weapon configuration, an operational bolt catch feature, and a rear wired wiring harness for easier installation of after market rail systems than previous ERG models. Similar to real AR15 style rifles the RM4A1 ERG’s modular design allows limitless customization options to best suit the individual’s training and MilSim needs."