The SSG-BSN 4-Row, 7.5-Foot Low Rise Bleacher is specially designed to accommodate 4 rows of seating without the need for chain-link fencing. The frames are made of 100% welded aluminum angle, and the first row has a seat height of 12" while the top row has a seat height of 30". The planks are 10"W and made of anodized aluminum. These preferred models come with double-footed boards on all rows. Check local building and safety codes to ensure bleacher compliance. Specifications: Frame Material: 100% Welded Aluminum Angle. Seat Height: 12" (First Row), 30" (Top Row). Plank Width: 10" Features. Double-footed boards on all rows