Dakota Alert 4000 Long Range Wireless Doorbell and Universal Button Alert System - The Dakota Alert Long Range Wireless Push button and Door/Window Sensor can be used in three different modes: Wireless Doorbell Button - In this mode, the doorbell button is mounted where needed Wireless Door Windows Open Sensor - in this mode the included magnetic sensor is mounted on a door or window to detect when it has opened Wireless Universal Transmitter - in this mode there is an input on the wireless tran Doorbell Button, Doorbell Chime, Wireless Transmitter, Wireless Doorbell, Home Automation, Electronic Products