Mounts in any 19" 2Post relay rack Compatible with 3" to 8" uprights Works with square, round or threaded holes racks Fully configurable shelf 300 lb (136 kgs) capacity Supports electronic equipment up to 29" (736 mm) deep Adjustable Depth: 3" - 8" (76 - 203 mm) Shelf can be mounted up-side-down Shelf options include flanges up, down, or up and down Optional straps & anti-slip mats secure equipment Made in the USA from 16 GA steel Features This Telco Rack Shelf is compatible with most 19" EIA Standard Telco Racks. The 29" Telco Rack Shelf has a 300 lb (136 kgs) equipment capacity and will support a wide variety of electronic equipment. Electronic Devices up to 29" (736 mm) deep can be supported on the Relay Rack Shelf. This 2 Post Rack Shelf comes with flanges up, flanges down or with one flange up and one flange down. See product names below to make the shelf distinction when making your online purchase. Transport and Seismic options are available for this Relay Rack Shelf if the installation requires.