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 2368mm/93.2 (L). The Slimline II Tray mounts to eight (8) supplied Feet that slide in to the supplied Track. The 2 x 750mm/29.5 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.