The ECS-270-18-4X-F from ECS Inc. International is a RF Quartz Crystal with Frequency 27 MHz, Frequency Stability ±50 ppm, Frequency Tolerance ±30 ppm, Load Capacitance 18 pF, Equivalent Series Resistance 30. Tags: Thru Hole. More details for ECS-270-18-4X-F can be seen below.