Dome Dimension: 34" x 26" x 4"Flange Dimension: 38" x 30""" Dome Dimension: 34" x 26" x 4", Flange Dimension: 38" x 30" Made of durable, impact resistant polycarbonate Industry leading quality skylight - Thicker and stronger than the original OEM skylight Take the dimensions of your skylight opening on your RV and compare them with this skylight to ensure a proper fit for your unit Use ICON Skylight Sealant for install MODEL NO - 12857