Add shelves to existing standard size four-arm racks, for folded apparel and cross merchandising. Chrome brackets support 13" x 24" plastic injection molded shelving (sold separately). Shelf holder brackets clamp onto 1" square tubing frame of standard size four-arm racks. Measures 12-1/4" deep x 23-3/4" wide. (Note: this item will not work with the high capacity four-arm racks with rectangular base frames).