1This is a set of 4040 right angle corner brackets for 4040 aluminum profile. 2Made from high quality aluminum, these corner brackets are durable and solid. 3Widely used to reinforce right angle corner joints of doors, windows, furniture, etc. 4There are total 6 pieces of brackets in one pack that you can use for many projects. 5Convenient to use, they can be simply fastened with bolts and nuts.