Corrosion-proof performance, proven Metro stability, and unrivaled value. All polymer shelves with removable, easy-to-clean 6" wide shelf mats. Shelves adjust in 1" increments. Lifetime warranty against rust and corrosion. Built-in Microban antimicrobial product protection to keep the product "cleaner between cleanings." Starter unit consists of four posts and the indicated number of MetroMax 4 shelves.