The ECS-120-12-30Q-EN-TR from ECS Inc. International is a RF Quartz Crystal with Frequency 12 MHz, Frequency Stability ±50 ppm, Frequency Tolerance ±30 ppm, Load Capacitance 12 pF, Equivalent Series Resistance 60. Tags: Surface Mount. More details for ECS-120-12-30Q-EN-TR can be seen below.