Except in the USA*, a sensor is not needed in order to use the Gogogate2 device. However, if you do not have a sensor, you will not be able to know if a garage door is open/closed, receive status/temperature alerts or trace garage activity in a built-in calendar.
The Gogogate Team strongly recommends getting a compatible sensor to fully enjoy the Gogogate2.

*Gogogate2 is compliant with UL325 regulations. See legal notice: Please make sure your garage door is closed before you start installation. The Gogogate product and our door sensors are meant to be used with garage door openers equipped with photoelectric safety sensors (manufactured after 1993). These sensors are normally found at the bottom of your garage door and avoid accidental closing of your garage door if an object or person is on the path of the door.