Raspberry Pi RTC Module DS1307 Real Time Clock Module with BAT and Coin Battery for Raspberry Pi
Amazon.com: XYGStudy Mini Base Board Designed for Raspberry Pi Compute Module 4 with Gigabit Ethernet/SD Card Slot/M.2 Slot CSI/DSI/RTC/FAN/HDMI/USB/RJ45 Connectors (CM4-IO-BASE-B) : Electronics