An optical cable split fiber box, also known as a fiber distribution box or fiber optic splice closure, is a device used to terminate, splice, and distribute optical fibers. It typically consists of two parts: an outer housing and an internal structure. The FOSC-450 is a single-ended, environmentally sealed enclosure for fiber management in the outside plant network. In this response, we will focus on the. 7. Now, the 2178 family includes many models and configurations for more flexibility to help meet the complex needs of today's fiber optic networks.