Skylight Inner Dome for a 22" x 14" Skylight opening. The smallest skylight opening it will fit is 21 1/2" x 13 1/2". An Inner Dome provides a layer of insulation and reduces condensation forming on the outer skylight. Molded of white ABS plastic material with a clear center insert. Complete your replacement with a new outer dome, SL1422. When paired with an ICON SL1422 outer skylight dome: the 2" depth is appropriate for a minimum 1 1/4" roof thickness, the 5" depth is appropriate for a minimum 4" roof thickness. Fits all standard 22" x 14" skylight openings. Opening Dimension: 22" x 14" Outer Dimension: 24" x 16" x 2" OR 5" Finish off your replacement with an ICON skylight | Icon Technologies Skylight Inner Dome, Low Profile, for SL1422 in White | ABS Plastic