Composed of both polymer and steel, MetroMax Q shelves are a superior storage solution. The durable open grid mat contains Microban antimicrobial product protection to inhibit bacteria, mold, mildew, and fungus growth, and easily removes from the rigid wire shelf frame for cleaning. And with a simple flip of the finger, the shelf can be quickly adjusted along posts to support storage changes. *Please note, these shelves are not compatible with MetroMax products manufactured prior to April 2009.