The ECS-300-10-37-JTN-TR from ECS Inc. International is a RF Quartz Crystal with Frequency 30 MHz, Frequency Stability ±20 ppm, Frequency Tolerance ±20 ppm, Load Capacitance 10 pF, Equivalent Series Resistance 60. Tags: Surface Mount. More details for ECS-300-10-37-JTN-TR can be seen below.