The ECS-120-18-23A-JGN-TR from ECS Inc. International is a RF Quartz Crystal with Frequency 12 MHz, Frequency Stability ±30 ppm, Frequency Tolerance ±20 ppm, Load Capacitance 18 pF, Equivalent Series Resistance 80. Tags: Surface Mount. More details for ECS-120-18-23A-JGN-TR can be seen below.