Post Shim Brackets are used to adapt both small and large Post Brackets to pole/post sizes smaller than 2" or 3" respectively in 1/8" increments - 1-7/8", 1-3/4", 1-5/8" 2-7/8", 2-3/4", 2-5/8", etc. When more than two shims are used together on a single post, welding the bracket to the pole/post is recommended.