I was using this in place of a doorbell at my home. Both the sensor and receiver have been tested and are working. It runs on batteries, but you can also use it by connecting it to a power outlet with a separately sold cable. There is no instruction manual. Setting it up is easy. I placed the sensor and receiver about the distance of one room apart, and it still received the signal and notified me properly. Due to aging, there is a general feeling of use, and the sensor is slightly yellowed. Please understand that this is a used item before purchasing. #MotionSensor #Doorbell #Security #NotificationChime