Tire and wheel attachments help keep automobiles on the road by assisting with tire maintenance, repair, and balancing. To keep air in tires, inner tubes and reliners replace punctured or damaged tubes. Patch cements and tire bead sealers adhere repairs and plugs to tires. Tire chains are attached to the treads of the tires to assist traction in snow and ice. To plug leaks, tire repair patches and sealants cover or fill up punctures. Tire changing machines and tire mounting tools aid in the removal of tires from rims and the installation of tires on rims. Tire chucks, inflators, and pumps are used to fill tires with air. Tire-pressure and tread-depth gauges measure the amount of air in the tires and the quality of the tread. Tire and wheel balancers guarantee continuous contact with the road and prevent uneven wear.