The CAP CER 3900PF 100V C0G/NP0 2220 is a type of ceramic capacitor. It has a capacitance value of 3900 pF and operates at a voltage of 100 V. The designation "C0G" or "NP0" indicates that it is a temperature-stable ceramic capacitor with low loss factor. This component is used in various applications, including electronics and communications equipment.