Sturdy anchor joints or brackets form corners for a basic raised bed 6 inches high. they are made of durable recycled plastic. They accept 2"x6" lumber (we do not recommend treated lumber) or composite timbers which you can purchase at your local lumber yard. The brackets bend to accommodate various shapes and designs - squares, rectangles, octagons and more. One anchor joint is needed for every corner of your raised bed design. If you would like a higher raised bed, purchase stacking joints (sold separately) that insert into the anchor joints.