Plastic shelving is supported on all sides by a steel frame and has a 400 lb. shelf capacity. Steel framing and posts feature an exclusive Nexelon™ finish that allows shelving unit to withstand wet, hot or cold extremes, impacts and chemicals. Includes a lifetime guarantee against corrosion. Nexelon™ finish consists of Nexgard, an anti microbial treatment to fight the growth of bacteria and molds. Removable, dish washable plastic storage shelving mats resist chipping and corrosion and include vents to increase air circulation and light penetration. Easily adjust at 1" increments on numbered posts for precise shelf alignment. Plastic Shelving includes 4 posts and 4 shelves. Easy tool-free assembly. Add casters to convert to a mobile storage unit. Choose from set of 4 casters, 4 casters with 2 locking casters or 4 fully pneumatic casters.