FOSC 450 Dome Closure, 576ct Single/1152ct Ribbon, 6 Ports, Includes (1) 72ct Tray, 29.65" x 11" 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.