This is the smallest of the FOSC 400 closures. It is intended for low fiber count cable splices and “tap-off” splices. Tap-off splices are those where most of the fibers in a cable are “expressed” uncut through the closure and only a few fibers are cut and re-spliced to feed a building or Optical Network Unit (ONU). The FOSC 400 A4 closure comes ready to store expressed loose buffer tubes. An optional slack storage basket is available for express stranded fiber and ribbon fiber.

As with all FOSCmore 400 closures, the slack storage and splice capacity of the FOSC 400 A4 closure depends on a number of factors including cable construction, splice type, and slack fiber lengths. Refer to the Closure Capabilities chart that follows for more details. less