AmerSeal Tire Sealant, a preventative-maintenance compound for commercial and industrial tires, can also be used for inflatable wheelchair tires. A liquid that's pumped into the tire through the stem, it coats the inside surface when the tire is rotated. If a puncture occurs, the tire's centrifugal force and internal air pressure cause the suspended fibers in the compound sealant to pack tightly around the puncture, thus preventing air leakage. When the puncturing object is pulled out, the tire should be turned to help force the sealant into the resulting hole.