The ECS-196.6-S-4X from ECS Inc. International is a RF Quartz Crystal with Frequency 19.6608 MHz, Frequency Stability ±50 ppm, Frequency Tolerance ±30 ppm, Load Capacitance 20 pF, Equivalent Series Resistance 40. Tags: Thru Hole. More details for ECS-196.6-S-4X can be seen below.