Post Clamp for Wesco Chrome-Plated Wire Shelving -- 1 each.Accessories for Wire Shelving Features: 5" x 1.25" stem casters. Choice of polyurethane or rubber wheels. Foot plates to bolt racks to the floor. Shelf edges to prevent items from falling. Extra shelves sold in pairs only. Leveling feet protect flooring and level racks on uneven surfaces. Post clamps join units together and "S" hooks are needed when adding shelves. Snap in 8" high shelf dividers keep shelves organized. Replacement posts sold in pairs only.