This line of NavePoint shelves is designed with flexibility in mind. The depth can be adjusted from 16 to 33 inches. It has slotted venting to reduce the possibility of overheating. Made of high quality cold rolled steel with a powder coated finish that protects them from rust and corrosion. Comes assembled. Please note that this shelf has a surface area of 16.2" x 21.7", which is fixed. The mounting rails can be adjusted from 15.5 inches to 33.3 inches.