Remote Adventure Design TRA-ADA Transit Exterior Ceiling Profile AdapterThis Exterior Ceiling Profile Adapter is designed to provide a clean, level mounting surface when installing a roof vent or fan on a Ford Transit van. This custom-profiled exterior adapter is shaped to match the contours of the Transit roof. It allows the vent fan to sit flush with the roof ribs, helping create a cleaner installation and eliminating the need to build up an uneven mounting area by hand. Note: This adapter is not designed to be installed over or along a roof seam. The adapter must be positioned in the appropriate section of the roof ribs for its profile to sit correctly. Installing it at a seam may prevent the adapter from sitting flush against the roof.Additional InfoOuter Dimensions16 ” x 16 “Inner Dimensions14” x 14″Thickness”Compatible withMaxxAir Deluxe series, Fan-Tastic Vent fans, and the 355 Airplus Deluxe Vent fans* Not compatible with MaxxAir Models 450