The ECS-400-8-30BQ-DS-TR from ECS Inc. International is a RF Quartz Crystal with Frequency 40 MHz, Frequency Stability ±100 ppm, Frequency Tolerance ±30 ppm, Load Capacitance 8 pF, Equivalent Series Resistance 30. Tags: Surface Mount. More details for ECS-400-8-30BQ-DS-TR can be seen below.