The SM-103 is an add-on wireless outdoor siren for SecurityMan Air-Alarm system. It features a receiving distance of up to 300 ft in open areas, a siren sound of 120 dB and an operating power of 100V - 240V AC. It has a run time of up to 100 hours and includes a built-in 6V DC rechargeable backup battery.MCYSM103. SM103. Security Man SECURITY MAN SM-103 Wireless Outdoor Siren.