With this new release from ICS, you can install an AR stock, especially the crane type of you want to put cranestock batteries... "For the majority of MP5 owners, ICS has developed and launched the unique AR stock adapter which allows the MX5 to not just accommodaye a larger sized battery pack, but also provide more dexterous tactical operations. The installation of the adapter is simple and easy in just a few minutes, and the package includes slig ring and mil-spec stock tube."