The BRK® C9120LBL (model SC9120B) is a wire-in, 120 VAC 60 Hz single and/or multiple station smoke and carbon monoxide alarm 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 SC9120LBL complies with UL 217, UL 2034, CSFM, NFPA 72, NFPA 720, HUD, FHA and other agencies that model their codes after the above agencies. They meet building codes where AC/DC with silence smoke and carbon monoxide alarms are required either separately or in combination. The alarms are interconnectable with up to 18 devices, of which 12 can be smoke alarms.