ASSEMBLES QUICKLY WITHOUT TOOLS. SHELVES ADJUST ON 1"" INCREMENTS. NUMBERED POSTS ALLOW QUICK POSITIONING AT DESIRED HEIGHT. CONVENIENT 4-WAY ACCESS. 5"" POLYURETHANE WHEEL SWIVEL CASTERS WITH DONUT BUMPERS. SOLID GALVANIZED STEEL 18-GAUGE SHELVES ARE FOR LONG LIFE AND DOUBLE WALLED FOR MAXIMUM RIGIDITY AND STRENGTH.