The ECS-49-18-5PLX-AGN-TR from ECS Inc. International is a RF Quartz Crystal with Frequency 4.9152 MHz, Frequency Stability ±30 ppm, Frequency Tolerance ±25 ppm, Load Capacitance 18 pF, Equivalent Series Resistance 150. Tags: Surface Mount. More details for ECS-49-18-5PLX-AGN-TR can be seen below.