The ETM option uses a cellular device connected to the tank’s gauge to send a signal every 24 hours to our office software so we know your exact propane level. The ETM option also allows the customer to monitor their tank level and propane usage on smart phone with an easy to use app. The electronic tank monitoring option when combined with the automatic delivery service gives you the peace of mind to know that they will not run out of propane gas. (NOTE: There may be an extra charge for ETM, please call for information.)