SecurityMan SM103 Wireless Indoor Siren for Air-Alarm1 and Air-AlarmII - Silver Add-on Wireless Indoor Siren For Security man Air-alarm System Receiving Distance: &gt;=300ft In Open Area Siren Sound: 120db Operating Power: 100v-240v Ac Add-on wireless indoor siren for SecurityMan Air-Alarm system Receiving Distance:300ft (In open area) Operating Power: 100 to 240VAC Siren Sound 120dB