Abstract: To minimize the space requirement inside a cassette and make cable retention force consistent and easy for fiber routing/rework, a cassette includes a cassette base molded to include a plurality of holders, a cassette cover to close the cassette base, and a plurality of blocks, respectively disposed into the holders, each of the blocks including one or more holes to accommodate one or more fiber cables. The fiber cables are fixed in the holes using a type of adhesive. In addition, bare fibers are placed inside the cassette to communicate respectively with the fiber cables.