Our 4" x 18" x 4 1/2" Kraft Open Top Bin Boxes are easy to assemble and made from strong 200# kraft corrugated material with a durable one piece construction. Our 4 x 18 x 4 1/2 Kraft Open Top Bin Boxes accomodate 18 inch shelves; ideal for organizing work areas or arranging materials and objects and can maximize your warehouse shelf space while organizing your inventory. All Bin Boxes have a write-on space located on the front panel for easy content identification. These Bin Boxes require no tape, staples or glue to assemble, 50 per bundle.