AA-Racks Model AX27 Aluminum Fullsize Van Rain Gutter Rack 2 Bar Ladder Roof Racks The AX27 features the Rust-free material of Aluminum. The package comes with a completed set of Mounting clamps & hardware. Our unique Three-bolt Lock design makes it compatible to most van roof rails,while keeping the stability for the loads, it is also easy to install & uninstall. The Extendable Top Bar allows the AX27 to fit in different width of van roof. The top bars extension ranged from Min 56'' ~ Max 63" The Rope Hook on the side of all four uprights provides the security for tying the tools or loads. Rubber Cap on each upright prevents water leakage and wind noise. Two Aluminum Adjustable Ladder Stoppers prevent ladders from sliding down.