Here are a selection of handy magnetic level indicators, you stick one on the bottle and it tells you how much gas you have left.
If you your bottles are kept outside ( IE. propane for your cooker ) choose an indicator that gives both winter and summer readings.
This is because the gas in your bottle is stored liquid form and gets more dense in the winter, so the level drops, a single reading indicator will give a false reading in the winter
Do not place over bottle seams as will stops the indicator from working properly.
Please note: These indicators are for guidance only and are not 100% accurate. For greater accuracy use a bottle gauge.
We advise reading the reviews before buying.