Design and functionality when this device was great for a moment. After a few days, I noticed the settings reverted to default, metric readings. I'm in the US so I changed the settings to SAE. I wrote to the seller and he replied that I needed to change the settings using the instructions that came with it. I told them I changed the settings according to the instructions and reread the first message I sent them. You obviously didn't read it to the end. Since I didn't get a response from them, I continued to use the device. I had to reset to SAE about 4 times. Finally, the last time seems to be set. Now the device is completely dead and won't even turn on. The internal battery was constantly charged by the built-in solar panel while the car was parked outside. I can turn it on with the USB cable, but it won't turn on again without a network connection. For some people, this can be a handy workaround. For me it is not. I bought this unit because of the solar power capability. One less cable hanging around the dashboard, nice and clean. It's also safer to have fewer objects in view. I have another car with a similar solar powered TPMS system. It works great and is about three years old. Unfortunately it has been discontinued. I will try another system and buy from another seller.