MATERIALS The storage shelves are made of Steel frame for strength and powder coated finish for resistance to corrosion,0.3" E1 MDF board. CAPACITY This shelving storage unit can hold up to 330lbs per shelf.(evenly distributed) RIVET LOCK DESIGN The shelves are supported by double-riveted beams and braces, assembly is no need nuts and bolts, instruction included, a rubber mallet recommended. ADJUSTABLE HEIGHT Height adjustable shelf design suitable for stuff in varied sizes. RUBBER FEET Four rubber feet for safety stability and floor protection. MULTIPLE USES The standing shelving unit are suitable for organized and storing, ideal used in a variety of office, industrial, educational, and residential settings. PACKAGE INCLUDED 3pcs x 5 tier shelf(59.1 x 27.6 x 11.8’’(HxWxD) per unit) Please Note: To help prevent any undesired injury, it is advised to wear gloves during assembling.