Sungmoon Electronics

Sungmoon Electronics makes metal-deposited plastic film used inside capacitors, components that store and release electrical energy in electronic circuits.

It supplies this material to capacitor manufacturers, who in turn use it in products such as electric-vehicle charging systems, solar and wind-power inverters, and industrial power electronics. Listed on KOSPI, Korea's main stock exchange, the company earns the large majority of its revenue from this single film product line, with a smaller direct-mail and parcel-delivery business making up the remainder.