The CAP CER 4000PF 400VAC Y5U RADIAL is a ceramic capacitor with specific characteristics. It has a capacitance value of 4000 picofarads with a tolerance of ±20% and can withstand a voltage of up to 400 volts AC. The component is classified as radial, meaning it has leads protruding from opposite sides of the disc-shaped body. Its classification under Y5U indicates compliance with certain standards for ceramic capacitors in specific environments.