The ECS-80-18-4XDN from ECS Inc. International is a RF Quartz Crystal with Frequency 8 MHz, Frequency Stability ±100 ppm, Frequency Tolerance ±30 ppm, Load Capacitance 18 pF, Equivalent Series Resistance 80. Tags: Thru Hole. More details for ECS-80-18-4XDN can be seen below.