The part number CAP CER 390PF 250V C0G/NP0 2220 refers to a specific ceramic capacitor. This component has a capacitance value of 390 picofarads and operates within a voltage range of 250 volts. It falls under the C0G or NP0 temperature coefficient class, denoted by its part number as well. The 2220 identifier signifies the size and form factor of this capacitor.