Made of 16 Gauge steel, Hergo mounting shelves are the most heavy-duty and durable on the market. The side brackets are manufactured with 11 Gauge steel and can be ordered in an upward or downward mounting style.  Each 18.5"D shelf surface is enhanced by 3 bends, in-front and back. The user can reverse shelf orientation from front to back, if so desired. Shelves are shipped with the back bend upward to secure equipment in place and prevent it from falling off the back of the shelf. Weight capacity is stated at 350 lb. for each 36" length when items are equally distributed. Hergo recommended weight capacity is stated at 33% of the total amount of weight placed on the shelf before the brackets start showing signs of fatigue. We do not recommend loading shelves above the specific stated capacity. Other available widths: 30", 36", 48" and 60".