Package: 1 EaRange Up To .5 Milesalerts With Light & Sound When Vehicles Or Pedestrians Approach Perfect For Home, Business, Property & Worksite Easy Installation and easy Operation Weatherproof Outdoor Sensors With Adjustable Sensitivity Control Expandable Up To 4 Sensors
- Unique sound and light pattern on the base unit identifies which sensor has been to install
- no wiring required. Base units uses AA batteries or included AC adapter.