If you’re enjoying the summer, there is a chance you’re using the inferior BBQing method known as the propane grill. Aside from it being a well known fact that cooking with propane is inferior to charcoal, you also have to deal with fill levels on your tank. How do you know it’s empty? You can knock on it, shake it, or lift it… all in an effort to figure out how much is left. Or, you can spend $90 and get the Truma LevelCheck. It’s a dead simple device that uses ultrasounds to check for liquids. Press it against the side of the tank, and an LED will tell you what’s on the other side: green means liquid, red, no liquid.