4-TIER SHOE RACK WITH DURABLE AND STURDY STRUCTURE: Made of powder-coated metal tubes and high quality plastic parts.The diameter of metal tube is 13.2mm,which enables this shoe rack load much heavier duty and more durable while using.And the powder-coated finish does not rust or corrode with normal use.20-PAIR SHOE RACK WITH LARGE STORAGE SPACE AND PERFECT FOR BOOTS:Fit about 4 or 5 pairs on each shelf.Totally 4-tier shelf can store 16 pairs of mens' shoes and sneakers or 20 pairs of heels.The distance between each tier is 7.48