This is a fiber optic cassette for a 4-bay interchangeable patch panel with 12xCS In and 12xALC Duplex Out, single-mode duplex OS2. It is a highly flexible fiber management unit that can be used stand-alone or integrated into fiber optic patch panels. Additionally, we supply other types of high-quality cassette designed to reduce installation time and cost for optical network infrastructures in the premises environment. All of our products are 100% guaranteed to work, providing you a cost effective solution for all of your network upgrade needs.