Low Power Consumption, Data transmitting, Real-Time Clock, quartz watch crystal

 ABM7 Series 20 MHz ±30 ppm 18 pF -40 to +85 °C Mini Microprocessor Crystal

https://www.futureelectronics.com/p/electromechanical--timing-devices--crystals/abm7-20-000mhz-d2y-t-abracon-9878141