These shelf support brackets by Prime-Line Products are constructed of stamped steel and come in a white powder-coated and corrosion-resistant finish. These support brackets feature a reinforced design to help support deep shelf boards, and they are ideal for use in closets, pantries, garages, sheds, basements, work shops, offices, and in many other applications. Each arm has three pre-drilled mounting holes, and they install easily with a few simple tools. Note: must be fastened to solid surface, or underlying studs to ensure strongest hold.