Today while traveling down to Texas on a round about loop to Arizona the Pressure Pro went off in heavy interstate traffic. I was down to 88 pounds of on one of the trailer tires. We have onboard air on the truck, so after pulling over on the shoulder, I quickly aired the tire back up to 110 and drove to a safer place about 50 miles down the road. I kept monitoring the tire's air pressure while in route. Finally put the spare on, later when we took the offending tire down to get repaired it was found to have a small paneling nail in it. Thanks to Pressure Pro, and to this forum for pointing me towards buying it, you probably saved the side of our rv from serious damage!!!!