This shelving unit features beams with rivets for a quick and easy boltless assembly. No hardware needed! The heavy duty frame is constructed of 14 gauge steel with a tan powder coated finish. Each of the four shelves on this unit are made of 5/8" thick particle board supported by double rivet beams on the top and bottom with single rivet beams in the center. Dimensions measure 48" x 24" x 72" (W x D x H). Keep your back room organized by storing supplies and back stock on this shelving unit. NOTE: Use of a rubber mallet is recommended for assembly (not included).