Standard 90° Folding: In order to ensure that each shelf bracket can be placed at 90° to the greatest extent possible, we add a rigorous selection process before the shelf brackets are packaged. The standardized 90-degree design is the objective factor to ensure that the items remain level and do not tip over after being placed on the board. Sturdy and Durable: The shelf bracket is made of thick and sturdy iron, it can support up to 75kg, no bending, super durable, corrosion and rust resistant. Adjustment range: This 0.5cm thick shelf bracket fits shelves with a width of 10-15cm. For wooden, plasterboard and concrete walls: No need to worry about you can't use our heavy duty shelf brackets on the wall you want. These black shelf brackets can be used on wooden wall, drywall and hard concrete wall. EASY INSTALLATION: No special skills are required to mount these open floating shelf brackets on the wall. Equipped with mounting screws. Shelves not included.