"Keep trailer contents securely in place during transport with this easy-to-use cargo bar. Simple mechanical lock will not vibrate loose. Keeps trailer contents securely in place when trucks move, helping to eliminate damage to the load Easy-to-use design fits between trailer walls 4 in. square articulating steel end plates feature rubber pads for positive gripping action Simple mechanical lock will not vibrate loose Constructed of 14 ga., 1 1/2 in. galvanized steel square tubing that won't bend or give"