The ECS-200-S-7SX-TR from ECS Inc. International is a RF Quartz Crystal with Frequency 20 MHz, Frequency Stability ±50 ppm, Frequency Tolerance ±30 ppm, Load Capacitance 20 pF, Equivalent Series Resistance 50. Tags: Surface Mount. More details for ECS-200-S-7SX-TR can be seen below.