With clear line of sight the range can be up to 200 feet or more.
With obstructions in between the sensor and your phone or receiver, it will be shorter. When installed on an RV, the sensor will be detectable practically anywhere in the trailer. When used on a outdoor grill, it can be detected in most rooms in the house. Range will be improved if you add spacers or keep the sensor away from the ground or add a few inches of separation between other metal flooring.