The ECS-554.666-10-33-AGN-TR from ECS Inc. International is a RF Quartz Crystal with Frequency 55.46667 MHz, Frequency Stability ±30 ppm, Frequency Tolerance ±25 ppm, Load Capacitance 10 pF, Equivalent Series Resistance 40. Tags: Surface Mount. More details for ECS-554.666-10-33-AGN-TR can be seen below.