Removable Accu-Level Propane Tank Gauge with Magnetic back
This Removable Accu-Level (r) Propane Tank Gauge utilizes a very special yellow ink. When slightly heated, this ink will change color from yellow to orange. Upon cooling, it will change back to yellow, There is nothing that gets used up or wears out. Easy to Use: Attach this Propane Tank Gauge on the side of your 20lb tank. Pour a cup of hot water down the Propane Tank Gauge. Immediately the entire Gauge will turn orange. However within a few seconds, the lower portion will return to yellow. This returned yellow color is below the surface of your propane. The gauge holds this activated color for about 30 seconds.