The ECS-115.2-18-5PXEN from ECS Inc. International is a RF Quartz Crystal with Frequency 11.52 MHz, Frequency Stability ±50 ppm, Frequency Tolerance ±30 ppm, Load Capacitance 18 pF, Equivalent Series Resistance 50. Tags: Surface Mount. More details for ECS-115.2-18-5PXEN can be seen below.