The CAP CER 3900PF 250V X7R 0603 is a type of ceramic capacitor with specific characteristics. It has a capacitance value of 3900 picofarads and an accuracy rating of ±5 percent. The operating voltage for this component is 250 volts, and it follows the X7R dielectric classification. This capacitor comes in a 0603 (also known as 1608 metric) case size.