The 21" green epoxy finish pressure-fit shelf divider can easily organize and create space for the contents of the wire shelving unit. the shelf dividers are made of epoxy coated iron wire for strength and durability. the green epoxy coating allows the shelf dividers to be used in wet environments such as a commercial kitchen walk in freezer, wine cellar, to other commercial or residential setting. can be used to customize the storage space to fit your needs. the green epoxy finish pressure-fit shelf divider is an optional accessory to the wire shelving unit. the pressure-fit shelf divider is nsf certified.