This gauge reads 2/32 less than the actual tire depth measured with a digital gauge. The big problem is that you think you have less tire depth than you actually have. I got new tires from my Harley-Davidson dealer and used this shop to check the tire depth - it showed at least 2/32. I took the bike back to the dealer - they used their digital gauge to show me the new tires were to spec. If you use this sensor, buy new tires ahead of schedule when you have thousands of miles (or more) of tread depth! It's too late for me to return this sensor to the seller so it looks like I'm stuck with it now.