The part number CAP CER 1.5PF 50V C0K 0603 refers to a specific ceramic capacitor with the following characteristics: capacitance of 1.5 picoFarads, a tolerance of ±0.25pF, and a voltage rating of 50 volts. It uses the C0K dielectric material in a 0603 (also known as 1608 metric) package size.