Easily attachable to extend the length of an existing starter unit, add-on boltless shelving is an economical solution for more storage space. Attaches to existingboltless shelving starter unitto increase storage capacity Offers unobstructed visibility of items Made of 14-gauge, powder-coated steel 3/4"w x 2-5/8"hdouble rivet angle beams, adjustable on 1-1/2" centers Optional 5/8" thick particle board decking Configurable with casters (sold separatelyhere) To ensure rivets are properly set on posts, firmly tap beams with arubber mallet. Availability:Stocked in our warehouse. Ships next business day.