The ECS-271.2-10-37-CKM-TR from ECS Inc. International is a RF Quartz Crystal with Frequency 27.12 MHz, Frequency Stability ±10 ppm, Frequency Tolerance ±10 ppm, Load Capacitance 10 pF, Equivalent Series Resistance 60. Tags: Surface Mount. More details for ECS-271.2-10-37-CKM-TR can be seen below.