All aluminum seat planks and under structure provide a lightweight, stable bleacher that is easily tipped for mobility. The 10"W aluminum seat planks have a non-skid surface for added safety. Transition foot prevents floor marking and four 4" non-marring, smooth rolling, swivel casters make moving easy. Recommended for indoor use only. Bleachers have 3 rows of seats. The 21'L bleachers seat up to 42 people. Bleachers come with a natural aluminum finish, but are shown with an optional powder coated blue paint. For pricing and powder coated color options, contact our bid department.