MetroMaxr 4 Mobile Shelving Unit, four tier, 48 in W x 18 in D x 68 in H, (4) open grid polymer shelves with removable shelf mats, unit load capacity of 750 lbs., (4) polymer MX63UP posts, wedge connectors, (4) polymer casters (2 swivel & 2 braked), built in antimicrobial product protection, NSF