Low profile beams to provide more storage space between shelves. Double rivet beams at top and bottom of unit form a rigid structure. Shelves are adjustable in 1-1/2 in increments. No nuts, bolts or shelf clips. For garage, industrial, basement, warehouse and office. 3/8 in Particle board decking. Commercial strength 16 gauge posts. Can be assembled as a 60 in unit or two 30 in workbenches.