The ICON SL2222 Skylight Inner Dome is designed to fit a 21-3/8" x 21-3/8" skylight opening.• Finishes the look of your skylight with a 1-1/4" white flange• Clear inner dome• Easy installation• Fits all standard 21-3/8" x 21-3/8" skylight openings• Opening Dimensions: 21-3/8" x 21-3/8"• Outer Dimensions: 24" x 24" x 4" Clear inner dome Easy installation | Icon Technologies ICON SL2222 Skylight Inner Dome in White