Custom G-Series Curb Mounted GSD Series Permatherm Acrylic Pyramid Shape Double Dome Skywindow - Minimum 3-1/2" Curb Height Required - Outside Curb Dimension: 45-1/2" x 70-1/4", Daylight Opening Square Ft: 14.14' - For use with curb and flashing supplied by others - Wasco uses high molecular weight acrylics in the GSD - No minimum pitch required - Not for vertical applications