This is a 1.5 kV ceramic capacitor with the designation CAP CER 27PF 1.5KV C0G/NP0 2225. It has a capacitance of 27 pF and is rated for 1500 volts, or 1.5 kV. The C0G/NP0 material classification indicates that it is a stable, temperature-insensitive ceramic capacitor suitable for use in applications such as filters and resonant circuits.