Safety Technology International, Inc. STI-34108  8-Channel Receiver - Part of the Wireless Alert Series Monitors up to 8 different STI devices at one convenient location Supervised for low battery and connection Operates up to a 1,000 foot line of sight range from sensors Turns on a siren, sounds a chime, triggers a normally open or normally closed switch, or turns on an external 12 VDC output 433MHz with dual antennas for increased signal strength