I use these tags on all my fuel/propane containers. I manually turn the indicator dial as I use the container and I can tell their status at a glance, even across a crowded garage.
Be careful when gluing on the knob so that you do not glue the indicator dial in place. The dial has to be free to turn when all is said and done.
Add a short length of paracord or other string to attach the completed tag to your container.
The author marked this model as their own original creation.