The ECS-100-20-5PXDU-TR from ECS Inc. International is a RF Quartz Crystal with Frequency 10 MHz, Frequency Stability ±100 ppm, Frequency Tolerance ±30 ppm, Load Capacitance 20 pF, Equivalent Series Resistance 50. Tags: Surface Mount. More details for ECS-100-20-5PXDU-TR can be seen below.