Reduced height design saves valuable rack space and perforated shelf keeps equipment cool, includes bottom ventilation for enhanced airflow circulation. Mounting hardware not included. 19" version holds equipment up to 17.75"W x 19.8"D (450.9 mm x 503.4mm). Mounts on 3"D (80 mm) double-sided racks only. Made of strong, lightweight aluminum; supports up to 60 lb (27.2 kg).