The Edsal HR153060 is a standing four-shelf unit with a steel rack and shelves made of particle board to support a 250-lb. per shelf capacity and to support a 1000-lb. total capacity when the weight is distributed evenly across all shelves. The steel beams on this unit are seated on corner post tab slots for support of the particle board shelves. Steel corner post couplers have tab holes on each side for joining the top and bottom posts securely together. This unit is open on all four sides to facilitate access to shelf contents from any angle.The assembled unit is 60 x 30 x 15 inches (H x W x D). (H is height, the vertical distance from lowest to highest point; W is width, the horizontal distance from left to right; D is depth, the horizontal distance from front to back.) This shelf unit has a tab and slot design for boltless assembly. Assembly instructions are included. A rubber mallet (sold separately) and small screwdriver (sold separately) are recommended for assembly.Standing shelf units are commonly used to store items to help create organized, efficient, and safer work areas. These systems typically consist of a frame or rack with open shelves. Added components such as casters, wheels, or handles are used for applications that require mobility. Standing shelf units are used in a variety of office, industrial, educational, and residential settings.Edsal Manufacturing Company manufactures storage systems and industrial furniture. The company, founded in 1952, is headquartered in Chicago, IL.