The NDR intercom system provides the same features as the NEM, but with the added ability to selectively control remote devices (such as door strikes, maglocks, lights, alarm contacts, and others). Masters are available in 10, 20, 30, and 40 station sizes, with or without a handset. Add-on selectors in 20 or 40 station sizes can be connected to expand the system’s capacity. Single or dual master system (w/adaptors), and fully intermixable with all NEM series components.