Model HZM | - Z is an intelligent device that connects a single zone of conventional devices to an analog loop. Model HZM | - Z can power up to 15 two-wire ionization and photoelectric smoke detectors (Siemens Models ‘3’ or ‘11’-series). Model HZM | - Z can power one (1) beam detector (Model PBA-1191) with no additional devices, and can also monitor listed alarm-causing shorting devices, such as: water-flow switches, thermal detectors, manual stations, etc.