The ECS-135.6-10-33QZ-TR from ECS Inc. International is a RF Quartz Crystal with Frequency 13.56 MHz, Frequency Stability ±50 ppm, Frequency Tolerance ±15 ppm, Load Capacitance 10 pF, Equivalent Series Resistance 120. Tags: Surface Mount. More details for ECS-135.6-10-33QZ-TR can be seen below.