I bought it on December 16th and didn't use it until summer 17th. I went on a long motorcycle ride in September so I wanted to check my tires. The sensor pointed a little higher. I checked all the sensors I had and it definitely showed a high reading. The device filled and bled fine, so I had to ignore the pressure gauge. I figured I just had to buy one more and Revain wouldn't let me do anything at that point. Fortunately, JACO has a contact link on the site. I sent a short email explaining my concerns. The owners responded quickly, sincerely apologized and took care of me quickly and also provided a replacement calibration. I'm so glad when I see such old school customer service. I believe that we can all have problems in business and products, but the way problems are solved shows the true nature. JACO has a customer for life. Knowing that these people care about the safety and satisfaction of their customers is better than a few good and bad reviews.