This Rack Kit is for truck camper shells and trailers that have roof top sizes no larger than approximately 1425mm/56.1'' (W) x 752mm/29.6'' (L). The Slimline II Tray mounts to four (4) supplied Feet that slide in to the supplied Track. The 750mm/29.6 long pair of tracks can be easily mounted to your canopy/shell or trailer.See the Track installation instructions in the INSTALL tab for further details.This taller kit has space for mounting the Front Runner tables or other compatible accessories under the rack.