Multi Media Masters Switzerland

Multi Media Masters and Machinery SA (4M), based in Yverdon, Switzerland.
Master and stamper production for CD-Audio and CD-ROM, injection molding of CDs, CD-R replication and DVD manufacturing/replication.
Operating under this name from October 1988 until June 2002, when it was renamed as 4M Systems S.A.
In July 2006, merged with ASCII Ingénierie S.A., based in Monthey, into 4M Technologies S.A., giving up optical media manufacturing.
Mondema S.A., a limited company founded in 2008, took over the assets of 4M Technologies on January 1st, 2009. In these cases the customer name will appear in the matrix.

Mastering SID codes "L 851" and "L 852" are almost exclusive when mastering code occurs, and commonly written with a space after the "L".

These mastering codes can be found on many CDs mastered for manufacturer elsewhere. Examples are the Danish manufacturing plant Tocano between 1995 and 1997 and Ablex in the UK.