The modular pergola system is an assortment of brackets to be used with 4x4 (3.5”x3.5”) wood that is available at over 40,000 lumber suppliers in North America. Wood should be dry for installation, as freshly pressure treated or wet wood from outdoor storage may not fit until dried out. We suggest you take a bracket with you when purchasing lumber, slide it on the ends of the wood to ensure proper fit.Metal brackets have two-stage rust protection built from 14 gauge zinc coated steel then given