Do you own and use a gas BBQ grill? Here's a handy hi-tech tool to make sure there's enough fuel for the fire before the backyard party gets started. The Truma LevelCheck uses ultrasound to accurately determine how much liquid gas is still inside a propane canister. The device's LED turns green if there is enough fuel within, or red if it's time to refill or replace. The LevelCheck works with propane, butane, steel or aluminum LPG gas cylinders, also doubling up as a mini LED flashlight. Backyard grillers, aka Dad, would probably love one of these in his pocket.