The ECS-250-18-4X-DU from ECS Inc. International is a RF Quartz Crystal with Frequency 25 MHz, Frequency Stability ±100 ppm, Frequency Tolerance ±30 ppm, Load Capacitance 18 pF, Equivalent Series Resistance 30. Tags: Thru Hole. More details for ECS-250-18-4X-DU can be seen below.