This Heavy-Duty Adjustable Shelf is a vented and fixed position shelf that is ideal for use in mounting heavier equipment in most standard floor enclosures and 4-post open frame racks. These shelves are available in two sizes, 18″ and 26″ deep, to accomodate most standard enclosures have an equipment weight capacity of up to 250 pounds. They come complete with a set of #12-24 mounting screws and have a black powdercoat microfinish to match rack and enclosure color.