M4 ELECTRIC DUAL MAGAZINE AEG 800R (ULTRA-CAP|AUTO-BUTTON) (TAN)One Full Metal Hi Cap M4 Magazine not enough? see NUPROLs electronically controlled double magazine assemblies. Two Hi Cap metal magazines joined together to provide a whopping 800R capacity. Features an electronic tensioner merely hold the button toward the front of the magazine to keep the BBs coming. Alternatively, purchase the "SC" (Sound Controlled) version that maintains tension as the shots are fired. For when batteries run flat, a manual