The class enables composition of letters fitting into Swiss C5 & C6/5 windowed envelopes. No assumption is made about the language used.

The class is based on the standard LaTeX classes and is compatible with the LaTeX letter class. It is not limited to letters and may be used as a generic document class; it is used with the chextras package.

The author is Boris Oriet. The package is Copyright © 2008, 2009, 2010 Boris Oriet.