The CRAFTSMAN wire shelf mounts to VERSATRACK rail to create a flexible and convenient storage system. Compatible with the VERSATRACK shelf bracket accessory, sold separately. It can be used as a flat surface, or inversed to use a lip on the front and back that helps hold things on the shelf for a maximum of 50 lb. When used with VERSATRACK shelf brackets, two brackets hold one shelf; three can hold two shelves. This product is backed by a 1-year limited warranty.