Features of the Thule Crossroad Railing Roof Rack Built-in tool for easy installation and removal Rubber coated steel strap secures foot to side rail Requires squAre load bars (sold separately) 450 - 4 feet per pack 4502 - 2 feet per pack 45050 - 4 feet, locks and 50in. load bars 45058 - 4 feet, locks and 58in. load bar