THIS SPACIOUS MULTI SPORT TRUCK RACK TURNS YOUR TRUCK BED INTO A PENTHOUSE DUPLEX FOR YOUR GEAR. Clamps onto truck bed rails without any drilling sorry to disappoint you dentists out there. Fits a wide range of truck beds, compact 1136 to full size 1137. Sold in 12 sets single sets combine with towers on truck roof, or full set stands alone. Takes the whole gamut of Yak accessories, for full multi sport compatibility. Combines with round bars sold separately to perfectly match truck width. Heavy duty construction handles up to 300 lb.