The ECS-260-18-33-AEL-TR from ECS Inc. International is a RF Quartz Crystal with Frequency 26 MHz, Frequency Stability ±50 ppm, Frequency Tolerance ±25 ppm, Load Capacitance 18 pF, Equivalent Series Resistance 40. Tags: Surface Mount. More details for ECS-260-18-33-AEL-TR can be seen below.