The UFC Integrated Routing (IR) B Length Double Stacked closure is available with a Cablelok (Polypropylene) or Heatshrink (Flame Retardant Polypropylene) base. The base configuration of 28 round ports and 2 oval ports covers a cable diameter range of 4.0 – 29.0mm when using Cablelok mechanical seals and 6.0 – 35.0mm when using heatshrink. The mounting system is manufactured from Grade 304 stainless steel and the backplanes are aluminum extrusions which can accommodate up to 24 IR SE trays or 48 IR SC/SC-B trays or a combination of SE, SC and SC-B trays. The position of the mounting system allows easy access for the routing of the fiber on to the trays and provides storage space between the two backplanes for the storage of fiber loops. The trays and fiber optic routing module are white which makes it easy to see the color of the fiber elements as they are routed through the positive fiber management system. Fiber slot retaining blocks guide fiber elements in to the IR system, the foam pad on the retainer is partially cut through to accommodate a range of fiber counts. All IR system cover plates are colored blue identifying them as removable parts allowing access to the fiber and the fiber slot retaining block and tray retaining clips are colored red to aid in identification if they are dropped.