This is a small ceramic capacitor with the designation CAP CER 5.1PF 50V C0G/NP0 0201, featuring a capacitance of 5.1 pF and a tolerance of ±0.5pF, while operating at a voltage of 50 volts. It conforms to the C0G/NP0 dielectric and has dimensions matching the 0201 (0603 metric) package size.