Mopeka Pro Check BLE Sensor f/Water w/Grease Mounting Bracket [M1017073]Pro Check BLE Sensor for Water with Grease & Mounting Bracket With Mopeka Pro Check, you'll be able to accurately measure the capacity of your Propane Tanksanywhere, anytime. The PRO sensor combines all the best technology of our ultrasonic sensing for our best sensor performance ever. Features: Monitor your propane usage directly via Bluetooth from your mobile or tablet device through the freely downloadable "Tank Check" App from the Apple or Google