The part number is CAP CER 18PF 50V C0G/NP0 0402. It refers to a specific type of ceramic capacitor that has an approximate capacitance value of 18 pF ±5% at a voltage rating of 50V. The designation C0G/NP0 indicates its temperature characteristic, which is stable over a wide range of temperatures. This component has a metric case size of 0402 (1005), making it suitable for use in compact electronic devices.