Dual Rail Tray Install bolts, backing washers, washers, and lock nuts securing dual rail tray between two storage uprights using two 3/4" wrenches. Item Description Qty. 1 Dual Rail Tray 1 2 Storage Upright 2 3 Bolt, 1/2" x 4 1/2" 4 4 Backing Washer, 1/2" 4 5 Lock Washer, 1/2" 4 6 Lock Nut, 1/2" 4 Tighten hardware to 20-25 ft-lb (27-34 Nm). Parent topic: Install 42" / 72" Storages