Save Money. They give you no indication of your tire pressure. I hit a pothole, of which there are many, and the tire went flat, but this thing read happily I was fine. Drove to the nearest garage and the guy agreed the tire was flat. Not only is the rim bent, the tire isn't holding any air either. I'm glad I didn't spend much on them. I was just hoping they would give me a hint that I need air but they don't even do that. After my tire blew up, I bought a good tire gauge and tried to get into the habit of checking the air pressure again. The problem is finding a place to add air. I'll work on that.