Expanded Metal on 3 sides extends 48″ high above deck to help contain loads and improve visibility and airflow. Upper shelf is adjustable on 3-1/2″ centers for versatility, and can be positioned with 1-1/2″ lips either up or down. Shelves are 12 gauge steel. 3600 lbs. overall capacity with non-marking, long-lasting 6″ x 2″ polyurethane casters, 2 swivel, 2 rigid. Overall height is 57″. Additional factory installed adjustable shelves are also available.