Standard 90° Bend: To ensure that each shelf bracket can be placed at 90° to the greatest extent possible, we add a careful selection process before the shelf brackets are packaged. The standardized 90-degree design is the objective factor to ensure that 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 bear up to 75 kg, does not bend, is super durable, corrosion-resistant and rust-proof. Adjustment Range: This 0.5 cm thick shelf bracket fits shelves with a width of 10 to 15 cm. For Wood, Plasterboard and Concrete Walls: You don't have to worry about not being able to use our heavy-duty shelf brackets on the wall you want. These black shelf brackets can be used on wooden walls, plasterboard walls and hard concrete walls. EASY INSTALLATION: No special skills are required to mount these open floating shelf brackets on the wall. Mounting screws are included. Shelves are not included.