Tip-N-Roll Bleachers are easy to move on their swivel casters. Caster brakes keep the bleachers from rolling when stored. Non-marring rubber foot pads protect the floor. The seats are made of 2 in. by 10 in. anodized aluminum planks. These bleachers are generally used indoors. They may be used outdoors but should not be tipped up when there is a wind hazard potential. Assembly required.