1U 2 Post Rack Shelf - 7" Vented, Flanges Down mounts in any 19” 2Post relay rack. It has a shelf surface area of 7” x 17.5” (177 x 445 mm) and can hold up to 30 lbs (14 kgs). The rack is made of 16 GA steel and takes up 1U. 2 Post offers a variety of sliding or fixed shelves for 2 Post racks. They are able to withhold weight from 30 lbs (14 kgs) to 900 lbs (408 kgs). Also the shelves are compatible with threaded, square, or round hole racks, while giving an adjustable mounting depth. 2 Post shelves are designed to hold all types of equipment in any size or weight.