The ECS-35-17-4XDN from ECS Inc. International is a RF Quartz Crystal with Frequency 3.579545 MHz, Frequency Stability ±100 ppm, Frequency Tolerance ±30 ppm, Load Capacitance 17 pF, Equivalent Series Resistance 200. Tags: Thru Hole. More details for ECS-35-17-4XDN can be seen below.