Be kind to the expensive composite, poly or wood kayaks! Works great on round Yakima crossbars; when empty both J-Cradles can be loosened and tilt over flat so straps are easily reachable and gives the ability to drive into a garage! The Stainless 'J' has two mounts which can "straddle" the tower base - thus moving it "out" and closer for easier loading. Use the Stainless Steel Stacker J-Cradles to store the kayak on a wall with the optional Wall Clip Kit. Kayaks are less likely to dent when carried on their stiffer sides. Only two bottom Snaparounds to loosen for installation. Use Padded Back as Stacker to carry second kayak.