This is a 1206 size ceramic capacitor with the designation CAP CER 12PF 1.2KV C0G/NP0. It has a capacitance value of 12 pF and a tolerance of ±5%. The voltage rating is 1200V (1.2kV) and it falls under the C0G or NP0 type, which is suitable for applications requiring high stability and low loss.