Built around a heavy-duty base to prevent damage. Bright electro-zinc plated to prevent rust, prolongs attractive appearance. Rolls smoothly on 5" x 2" polyurethane casters, bolted to a welded caster pad for increased protection and durability. 11 ga. square 1-1/4" steel tube base and 1" 16 ga. round steel tube sides. Shelves sold separately. FOB Shipping Point.