When I first installed it I thought one of them was broken. Bad battery, bad karma? No, it just needed to be either warmed up or made to work. 60mph did it and both did well after that. It's an easy install - screw it into the tire nipples, tighten the lock nut, make sure you carry a wrench so you can add air once it tells you you're too low. A screen is mounted on the steering wheel to tell you what's going on. Reading with dark glasses on a sunny day is not easy, but it is possible. It has a red light warning when installed and it beeps, but probably isn't audible due to road noise. Very happy with this product - the accuracy shows how barometric pressure and temperature increase as you ride, even in one pound increments. It also informs you about important information before you embark on fun twists and turns. This was used on the BMW GS 800, which was often used off-road. It's nice to know the exact pressure and temperature after driving through puddles and mud before moving onto tarmac.