Bests & Worsts Reviews from Amazon

To everyone who wrote reviews about the gauge reading 'full' and then suddenly running out of gas, there is a reason for it. This item has a gauge that reads gas pressure, and you cannot determine ANYTHING about the level of propane in a tank by reading gas pressure. The description of this item's intended function is fraudulent. The only meaningful measurement for 'How much propane do I have left?' is the amount of liquid in the tank, and this item does not provide that information at all. That must be determined with a float device (measuring liquid level), or by knowing the full (or empty) and current weight of the tank (measuring pounds of liquid.) The pressure in a tank of any liquified gas is created by the liquid turning to gas, not by pressure being pumped in during filling. (Lookup 'vapor pressure' if you want the science.) There are variables for temperature, altitude, etc., but the vapor pressure is basically constant right up to the point where the last of the liquid vaporizes, then you're done. During use, the GasWatch gauge will read 'full' for hours while there is still liquid present, then drop to '0' within minutes. This might save the steak you have on the grill, but serves no purpose at all in planning your next event or RV outing. You are better off picking up the tank and sloshing it around to estimate what is remaining. That said, there are propane tanks with the internal float and gauge built directly into the tank valve. The GasWatch gauge is not that thing. Don't be fooled. I would have given this zero stars if possible, and don't even know how a product like this is legal to sell.