Further Detail The YARDLITE (RoofLITE) FENSTRO 4555 skylight is a cold room window used for maximum flexibility on all roofing types. It has 14 mm double glazing to provide insulation. Comes with an integrated flashings with apron. The Skylight can be installed easily, with top-hung and tide-hung opening options. It is weather and UV ray resistant. Suitable for roof pitches between 15°-60°.