This device is one of those that you pay for goods. It works, although it's about two psi. I installed it on Royal Star TD, the sensors connected quickly. It's not easy to set up as there are only two buttons. If you're older than smartphones, it's easy to understand. The screen is difficult to read with polarized sunglasses. The battery lasts well, rode for three days before needing to be charged. I use it to monitor tire temps and pressure changes in hot tires as we ride as a couple most of the time. For this it is very convenient. Runs out pretty quickly when charging. Anyone who complains about the loading process removes the lock for 5 seconds, that's okay.