[Sirkon]

Sunkyong Magnetic was a major worldwide OEM supplier of audio cassettes (DENON, MEMOREX, SCOTCH) as well as pancakes for professional duplicating facilities. It makes and sells audio cassette tape under the brand name of SMAT and SKC. Sunkyong Magnetic supplies 30% of the audio tape in the worldwide market. The annual production of cassette tape is 1.3 billion units. It is the largest supplier of cassette tape in the world. In 2012 they are still producing the compact cassettes.

http://vintagecassettes.com/skc/skc.htm