Please NOTE that the package does not include batteries. UP to 58 RECEIVERS/SENSORS EXPANDABLE: Bistee wireless receivers and motion sensors can be paired with each other up to 58, with 58 beautiful tones and 5 volume levels to choose from. The motion sensor is configured with IP44 waterproof, so it can work for you even if it is placed outdoors in the wind and rain. Once purchased, it has a 1-year warranty, any customer complaints, please contact us through the order, thank you!. ONE-STEP QUICK INSTALLATION & USE: Use 4 AA 1.5V alkaline batteries (batteries not included in the package) to power the motion sensor and fix it to the place that needs to be monitored (walls, fences, trees, etc.); plug the receiver into an outlet indoors, and you're done enable surveillance protection. The units are paired before shipping. 20 FEET WIDE MOTION MONITORING RANGE: Combined with customer complaints of this type of product, we have adjusted the monitoring range of the microwave infrared sensor to reduce false alarms caused by long-distance falling leaves/small animals/sunlight or wind or temperature changes. When a signal is detected in the working state induction area, a red light will flash to indicate 1S, and a wireless signal of 1S-433.92MHZ will be transmitted, so that you will not miss any visitor. 600 FEET LONG WIRELESS TRANSMISSION RANGE: After field testing and measurement in multiple scenarios, we have set the optimal wireless distance, the receiving range of the plug-in receiver and motion sensor is up to 600 feet (no obstacles), even if you need monitor a wide range of spaces, we can meet your needs too!. FIRST MICROWAVE-INFRARED COMBINED DRIVEWAY ALARM: Bistee brand has been focusing on security products for 30 years, and has developed the first microwave and infrared combined sensor with professional and leading technology, which can monitor more accurately, reduce false alarm rates, and better protect your indoor and outdoor properties. Ideal for driveways, front porches, gates, swimming pools, garages, sheds and more. Great for homes, businesses and malls. ?Please Note that the receiver is AC Powered, and the transmitter is Battery Powered. Please contact Bistee After-Sale through ORDER once you need!. Hi! Please Check the INSTALL VIDEO behind the Main pictures when you receiver the product!.