Aluminum Backing Plates are a great way to reinforce your dock ladder when using thru bolts to mount your ladder. The 23" long plates mount on the back side of your decking boards and distribute the weight across several boards versus just the board the bolts are attached to. Plates measure 23"L x 2"H x 1/4"D. Sold in pairs. | Dock Ladder Aluminum Backing Plates, Pair