This M4 Splice Cassette enables fast, field termination and provides cable management within the housing. The M4 Splice Cassette is designed for use with Single-Mode OS2 fiber, houses 12 fibers, and provides SC UPC Duplex ports. This cassette supports fusion splicing of individual fibers, with heat shrinks, pigtail slack and cable slack managed within the cassette. This eliminates the need for individual splice trays or housings, as well as allowing splicing to be done away from the rack housing in a suitable workspace as needed. The design of the cassette allows it to be easily mounted from either the front or the rear of an enclosure or panel. Individual fibers within the cassette may be accessed without disturbing the other fibers in the housing. -.