This Rack Kit is for truck canopies/camper shells/caps and trailers that have roof top sizes no larger than approximately 1165mm/45.9 (W) x 2166mm/85.3 (L). The Slimline II Tray and eight (8) supplied Feet mount onto the OEM/Factory installed track of your canopy/shell or trailer.NOTE: Additional fasteners may be required to fit OEM/Factory supplied tracks.