MTB Road Bike Bicycle Headset Stem Watch Digital Clock Headset Top Cap Stem Cover

The instructions are micro-printed (the kind you expect on a hidden clause in a contract). But after turning on the lights and figuring out how to set the time out was easy to install and looks nice. I find it great because it lets me know if I'm running late to work or not which is all I need (speed, cadence, rpm, etc. are honestly not important in the moment and I'm prefer to have them saved on my phone for later reference, with my phone in my bag for safe keeping).