The ECS-35-18-5PVX from ECS Inc. International is a RF Quartz Crystal with Frequency 3.579545 MHz, Frequency Stability ±50 ppm, Frequency Tolerance ±30 ppm, Load Capacitance 18 pF, Equivalent Series Resistance 150. Tags: Surface Mount. More details for ECS-35-18-5PVX can be seen below.