BUILT FOR HEAVY EQUIPMENT: With a 300 lb (136 kg) weight capacity, this 29' deep shelf is ideal for mounting large, heavy networking and IT equipment on a 2Post rack. VERSATILE INSTALLATION OPTIONS: Choose from flanged (equipment stop) options with the flanges facing up or down to best fit your mounting requirements. SECURE EQUIPMENT WITH STRAPS: Slots along the sides of the shelf allow for the use of equipment straps to keep your devices securely mounted. VENTED DESIGM: Available with vented bottom to accommodate equipment with varying airflow needs. COMPATIBLE WITH 2POST RACKS: Designed to center mount on standard EIA 19' 2Post relay and telco racks, fitting round, threaded, or square holes.