I bought a very nice racing gauge in Michigan while visiting my sister. I love it! I permanently attached it to a portable aluminum air tank and didn't want to take it off. I also have a trailer with tires that can be inflated to 120psi. That number doesn't go up that high. For these reasons I bought this one. I've searched extensively for the exact one. That's it! It matches the reading on my hybrid car's dashboard exactly, and matches the good gauge I got in Michigan exactly! If you don't get a broken one, you can trust all the reviews about its accuracy! It's well done. They include multiple fittings that screw into the base, so you can attach them to anything. One is for a standard air hose connector. There was no documentation at all. So it was a trial and error operation to figure out exactly how it works. The left button is labeled ON and the right button is labeled FUNC. It doesn't really make much sense, as the left one turns it on or off if held down (it also turns itself off after a minute or so), but works if pressed quickly and repeatedly. (PSI, BAR, KPA, KGF/CM2) The right switch turns the backlight on and off. But that's secondary because it's well done and <ACCURATE>! I got exactly what I wanted! A truly accurate pressure gauge with the ability to inflate and deflate, capable of reaching at least 150psi! (If I remember correctly, the product description says 150psi, 160psi, and 200psi. Batteries weren't included (AAA). Smaller too. I'm guessing it's worth twenty bucks. and it's not a piece of junk, always one these days big problem.