The ECS-35-S-1X from ECS Inc. International is a RF Quartz Crystal with Frequency 3.579545 MHz, Frequency Stability ±50 ppm, Frequency Tolerance ±30 ppm, Load Capacitance 20 pF, Equivalent Series Resistance 120. Tags: Thru Hole. More details for ECS-35-S-1X can be seen below.