Wire installation note requiredOperation: DC for RDB-38, AC for RDB-283-channel selection to avoid interference with other units or radio devicesCan be used as normal doorbell or S.O.S. alert for the sick and elderlyEffective distance: 15m (50ft.)Power source:-RDB-28 chimer: 120VAC/220-240VAC-RDB-38 chimer: 3 AA size batteries-Remote control: 9V (006P) battery
