The CAP CER 390PF 250V C0G/NP0 1808 is a specific type of ceramic capacitor. It has a capacitance value of 390 picofarads and operates at a voltage rating of 250 volts. This particular component belongs to the C0G, or NP0, class, which is known for its stable temperature characteristics. The metric size designation is 1808, corresponding to an 18 mil diameter and 8 mil height.