A module comprising: (a) a housing; (b) a tray mounted in the housing,
wherein the tray comprises at least: (i) a first and second submodule,
each submodule having one or more compartments for containing individual
add/drop filters; (ii) a first plurality of cascaded add/drop filters
installed in the first submodule; and (iii) a second plurality of cascaded
add/drops filters installed in the second submodule; and (c) connectors
mounted to the housing and optically connected to the fibers at the ends
of the first and second plurality of cascaded add/drop filters.
