The BRK® 9120LBL (model 9120B) is a wire-in, 120 VAC 60 Hz single and/or multiple station smoke alarms specifically designed for residential and institutional applications including sleeping rooms of hospitals, hotels, motels, dormitories and other multi-family dwellings as defined in standard NFPA 101. The 9120LBL complies with UL217, CSFM, NFPA 72, HUD, FHA and other agencies that model their codes after the above agencies. They meet building codes where AC/DC with silence smoke alarms are required. The alarms are interconnectable with up to 18 devices, of which 12 can be smoke alarms.