21.25"x21.25" Skylight Replacement Dome

Overall Dimension of Plastic (includes flange) 21 1/4" x 21 1/4" Flange 1 1/4", Dome dimension 18 3/4" x 18 3/4" Thickness .118 Approximately 1/8" Height of Outer Dome 4" Height of Inner Dome 3" Material: Acrylic or Polycarbonate (impact resistant) All inner domes are acrylic even if Polycarbonate is selected (only concerned with the outer dome being impact resistant) Dome tape only included with Double Dome orders Gradual Rise Profile (will not work with vertical rise or dome over frame units, contact us for helpful information regarding those shapes) We make all sizes! Please contact us if you need the size to be special. This product is designed for use in an existing residential/commercial framed gradual rise skylight where the frame and retainer are screwed together to hold the plastic in place.  There is no such thing as a STANDARD size or deduction between the Outside of the retainer frame and the plastic underneath.  Please remove screws and measure tip to tip of plastic pri