The ECS-166.666-12-36-AGM-TR from ECS Inc. International is a RF Quartz Crystal with Frequency 16.66667 MHz, Frequency Stability ±30 ppm, Frequency Tolerance ±25 ppm, Load Capacitance 12 pF, Equivalent Series Resistance 80. Tags: Surface Mount. More details for ECS-166.666-12-36-AGM-TR can be seen below.