A CAP CER 3900PF 1KV C0G/NP0 1210 is a type of ceramic capacitor. It has a capacitance value of 3900 pF and is rated at ±5% tolerance. The voltage rating is 1000V, or 1kV. This capacitor uses the C0G or NP0 dielectric material and has a metric case size of 1210.