The CX4 AT from IQD Frequency Products is a RF Quartz Crystal with Frequency 14 to 250 MHz, Frequency Stability ±10 to ±100 ppm, Frequency Tolerance ±100 ppm, Drive Power Level 100 to 200 µW, Load Capacitance 10 pF. Tags: Ceramic. More details for CX4 AT can be seen below.