A 0.3pF ±0.1pF ceramic capacitor with a capacitance of 0.3 picofarads and a voltage rating of 250 volts is specified by the designation CAP CER 0.3PF 250V C0G/NP0 0505, meeting metric dimensions and type classification as a C0G/NP0 (1B) capacitor in the 0505 package size.