I bought these tire pressure gauges to make it easier for me to tell when the tire is under-inflated. Installation is not difficult, very simple. In the weeks that followed, 3 out of 4 of my tires began to deflate very slowly. It got worse over time when my front tires (1 year old) were under-inflated or even deflated. It's no fun inflating a tire at a gas station when it's raining cats and dogs. I decided to take the car to a tire shop to check them out. When the tire fitter saw these tire pressure sensors, he immediately said that it is better to remove the tire pressure sensors because they are usually not stuck and cause air leakage from the tire. I immediately removed the tire pressure sensors and threw them away. Do not use such tire pressure sensors. They are rubbish and have never shown an under-inflated tire.