1. Adopt digital technology, emitter and receiver to not interfered by environment 2. Use super high-frequency wireless transmit signal mode,need not contact by wire,easy to use 3. Detector use advanced infrared detecting technology,working underall condition 4. Very suitable for home, offices, hotels, jewelry stores, etc. 5. Wireless installation, just place the sensor at the entrance 6. Battery: AAA*3 (not included)
