Guide Post Bracket with Hardware Guide post bracket conveniently guide your boat while also protecting your lift. 5 inch by 8 inch and 6 inch by 10 inch bottom I-beams. Each bracket is 12 inches high and holds a 1 and 7/8 inch PVC pipe for support. The guide post brackets are made from marine grade 6061 aluminum, and they hold guide pipes to conveniently guide your boat while also protecting your lift. Each guide post bracket is sold separately and comes with aluminum tabs and stainless steel hardware for easy installation. Our guide pipes weigh down the bottom cradle and double as PVC stiffeners.