 DS3231 Precision Real Time Clock Breakout. This has I square C to communicate with your microcontroller, it has a battery backup so it's always going to keep track of the time even when your project is powered down, and it has the Stem-AQT connectors to make it plug and play with your microcontroller projects. So the crystal is sitting there oscillating but the temperature can change that oscillation. So it has a temperature compensation so it can adjust the time that it's reporting based on any changes in temperature. I'm gonna plug that Stem-AQT cable into my real-time clock. It's gonna power up and then it is immediately gonna grab the time off of the chip. So I set this chip yesterday while I was setting up this project with the time and it has just been sitting there continuously running and calculating that time. So it just updated and now here we are 113 and 30 seconds. DS3231 Precision Real Time Clock Breakout with Stem-AQT.