FOSC 450 Dome Closure, 96ct Single/144ct Ribbon, 4 Ports, Loaded Without Trays, 19.09" x 8" Fiber Optic Splice Closures or Enclosures are used to hold and seal splices. Splice closures can be used in Aerial, underground or direct burried, pole/wall mount and pedestal or ground level applications. There are different types of closures such dome style, aerial terminal closures, runt closures, gator closures and many more.