FULLY EXPANDABLE SYSTEM & 1 YEAR WARRANTY: The driveway alarm is expandable to 58 sensors and receivers for full coverage of your outside/inside space.5 VOLUME ADJUSTMENTS AND 58 SELECTABLE MELODIES. Match different melodies to different sensors to differentiate where motion is detected, instantly protecting you and your family's life and property. PLUG-IN, QUICK INSTALLATION: Use 4 x 1.5V alkaline batteries (batteries are not included in the package) to power the motion sensor alarm, which can be mounted on a wall, fence post, tree or any other surface, then plug the receiver into an outlet to complete the installation. Units are set up for pairing prior to shipment. 600 FEET LONG WIRELESS TRANSMISSION RANGE: The motion sensor and plug-in receiver can receive alarm signals up to 600 feet (actual distance varies depending on the local terrain), so even if you have a larger perimeter or property to monitor, the driveway alarm is still there for you. The system uses advanced wireless transmission technology (FSK+FHSS) to avoid wireless signal interference from other devices. 20 FEET WIDE MOVEMENT DETECTION RANGE: The driveway sensor can detect people or vehicles or animals moving from 0 feet to 20 feet ahead. Improved motion detection chip (2023 new version) and detection angle (15 degrees vertically, 45 degrees horizontally) reduces false alarms caused by critters/sunlight/wind/dead leaves/temperature changes, etc. WIDELY APPLICABLE: BITIWEND Driveway Alarms Wireless Outside Weatherproof Motion Sensor can be used to monitor and protect your outdoor/indoor property. For example driveways, gates, porches, pools, garages, farms, etc. The motion detector works at all the seasons. Working temperature range from -10 to 130 degrees Fahrenheit. Please NOTE that the package does not include batteries. Please contact BITIWEND After-Sale through ORDER once you need!. Hi! Please Check the INSTALL VIDEO behind the Main pictures when you receiver the product!.