I have a very old electronic sensor that I keep in the glove box but lately it has been reading a bit high. I also have a couple of old pencil gauges that don't read the same thing. So I ordered this gauge from Summit Tools along with a new inexpensive Β£150 z. B. Electronic gauge for my truck (wish this gauge was over 60psi). it feels good in my hand. At 40psi, the new digital gauge reads no more than 1psi, so I find both to be fairly accurate. It also allowed me to confirm which pencil gauges were still correct and discard others. The gauge relief valve is quite slow - too slow to use with large car or truck tires, but makes it easy to get the right pressure in smaller tires.