This is a high-specification ceramic capacitor with the part number CAP CER 18PF 1.5KV C0G/NP0 1808. It has a capacitance of 18 pF and operates at ±1 deviation, with a voltage rating of 1500V (1.5kV). The capacitor is classified as C0G/NP0, which indicates its stable temperature characteristics and low dissipation factor. Its size is specified in both metric (1808) and imperial (4520) formats.