The WPA-3000 is ideal in locations where there may be deer or other large animals that would cause false signals with a motion detecting system. Also, because the probe is buried underground, it will be the least noticeable of our wireless systems. The transmitter is weatherproof and meant for exterior locations. Up to four zones can be monitored with additional transmitters. The transmitters can be programmed so they will each sound a different tone at the receiver. The WR-3000 is the standard receiver for our 3000 Series products. It plugs into a standard wall outlet and can be placed on a table or mounted on the wall. When the receiver gets a signal from the transmitter, one of four different tones (Classical, Westminster Chime, Ding Dong, or Whistle) will sound for a few seconds. There is also a volume control, allowing you to set the sound to the desired level. The WR-3000 is equipped with four form "C" relays (one for each channel), and one 12-volt DC output terminal that will activate for several seconds when a signal is received. The receiver can be user-programmed, so the 12-volt DC terminal and one relay will activate for 10 minutes, if this is desired. The tones will still sound for several seconds. *Actual range will vary depending on the local terrain.