What MetroMax shelves are corrosion-proof?

MetroMax 4 shelves are constructed of 100% rust-proof polymer. The shelves are completely corrosion proof and include a lifetime corrosion warranty.  

MetroMax i shelves are 100% rust proof and include a lifetime corrosion warranty.  

MetroMax Q is not corrosion-proof, but does include a 20 year corrosion warranty.