WIMA MKP 4C polypropylene compact film capacitors exhibit considerably smaller case sizes compared to the traditional WIMA capacitors. As an example, a 1.0 µF/630 V_DC capacitor has a smaller volume by 57%, and a 0.1 µF/630 V_DC capacitor would even be smaller (by 59%) than a conventional MKP 4.

In the MKP 4C metallized capacitors, thin layers of aluminum (approximately 0.03 µm) are vacuum-deposited on the insulating film as conducting electrodes. In the case of a breakdown, the short-circuit current causes the thin metal coating to evaporate around the point of failure and an insulating area is formed. The capacitor remains intact (self-healing). Due to their construction principle, metallized capacitors stand out for their very favorable capacitance/volume ratio.