The rubber strip provided can be attached to the truck topper cross bars to increase friction, keep stuff from sliding around. Truck cap roof ladder rack is made of reinforced aluminum, anti-rust and anti-corrosion. The workmanship quality is beyong your expectation, sturdy and durable. Maximum weight capacity is 500 lb.Also fit for van or trailer, such as Ford Transit, Ford Transit Connect, Chevy Silverado, Dodge Ram, etc. 2pcs 60'' crossbars, 4pcs 2.75 wide mounting bases, 4pcs endcaps. 2.8 total height clearance. Item type: Universal Roof Rack. Condition:100% Brand New Color: Black Material: Aluminum + Steel. (2.8 total height clearance). All of our stock inventory is listed. Please do not leave anything less than 5 star feedback before giving us a chance to do so. Universal Roof Rack with Hardware Set.