Product Size: H 1U Space; Deep 16-29 Inches; Both Deep and Width are adjustable. Material: All Metal, Cold rolled steel, No Plastic, Rounded edge , Durable and will never rust. Fitting APC, HP, IBM, DELL and Compag cabinets & racks Weight Capacity: The Rail sets are made of 16 gauge cold rolled steel and finished with Powder Coating. 16 Inches Deep can hold the Max weight of 120 Pounds; 29 Inches Deep can hold the Max weight of 44 Pounds. Including All screws for Assembly Rails together and 8 Sets of M6 Screw & cage Nuts.