The ECS-36-18-10X from ECS Inc. International is a RF Quartz Crystal with Frequency 3.6864 MHz, Frequency Stability ±50 ppm, Frequency Tolerance ±50 ppm, Load Capacitance 18 pF, Equivalent Series Resistance 200. Tags: Thru Hole. More details for ECS-36-18-10X can be seen below.