The main odometer worked, and the current speed, but none of the other screens worked. I did get customer service once after several tries; someone very knowledgeable helped me get the screens unlocked. But then every time I pressed the button to go to another screen, it would go for about a second and then go right back to the first screen. I kept pressing the button while on other screens to set them and then losing my main odometer mileage reading back to zero. I called and left messages. There are several choices of tech help voicemail boxes to call and leave messages. I tried all. I finally reached someone who said he would find out about my problem and call back. He didn't. I called and left more messages, even saying I had seen reviews on Amazon that said that Topeak's customer service was good. I was pleasant in my messages. Still no callback. This was last October, mostly. I since bought a different device but haven't installed it yet - too cold out there for me! 1 star