The ECS-240-18-20BQ-DS from ECS Inc. International is a RF Quartz Crystal with Frequency 24 MHz, Frequency Stability ±100 ppm, Frequency Tolerance ±30 ppm, Load Capacitance 18 pF, Equivalent Series Resistance 40. Tags: Surface Mount. More details for ECS-240-18-20BQ-DS can be seen below.