Check how much liquid propane is left for your grill, patio heater, or fire pit without having to touch the steel tank thanks to the EchoCheck Smart Propane Tank Sensor. The sensor is ready-to-use and maintenance free, whether you’re on a construction site or camping with friends. Just center and attach the sensor to the bottom of the propane tank's exterior. Then, enjoy the evening as the Bluetooth sensor sends instant, accurate, and reliable readings to the downloadable Tank Sensor by EchoCheck app on your phone.