I have a 5 wheel camper and experienced a flat tire that caused over $3,000 in damage. I think the problem was an improperly inflated tire. The tire gauge I used was from a local store and I only paid a few dollars for it. I felt like the sensor was failing me and I needed something reliable, so the readings I looked at when I checked my tire pressure were accurate. I bought this unit and found it to be as accurate as any professional mechanic in their shops. I tested it against some of the best. Also for each of you there is another good tool - TireMinder.