The CAP CER 3900PF 100V X7R 0805 is a 3900 picofarad ceramic capacitor with a tolerance of ±20% and a maximum voltage rating of 100 volts. It has an operating temperature range that starts at -55 degrees Celsius, which indicates its ability to function in various environments. The part number 2012 Metric suggests it conforms to the metric system used for measurements in many countries.