The ECS-250-20-4X-F-DN from ECS Inc. International is a RF Quartz Crystal with Frequency 25 MHz, Frequency Stability ±100 ppm, Frequency Tolerance ±30 ppm, Load Capacitance 20 pF, Equivalent Series Resistance 30. Tags: Thru Hole. More details for ECS-250-20-4X-F-DN can be seen below.