The GasCheck is a new device that allows users to determine exactly how much gas is in a propane tank before it runs dry. To operate, the rubberized tip of the pen-sized GasCheck is simply pressed against the outer wall of the tank at a 90-degree angle. It emits a high-tech ultrasonic signal to determine the liquid levels in the tank, signaling with a red light that there is no liquid at that level or a green light to indicate liquid is present at that level.
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