The ceramic capacitor is identified as CAP CER 390PF 1KV C0G/NP0 1812 with a capacitance of 390 pF and an operating voltage rating of 1000V. It falls under the C0G or NP0 classification, which signifies its stability over temperature. The dimensions are specified by the code "1812," equivalent to "4532" in metric units, indicating the physical size of the capacitor.