The Tweel (a portmanteau of tire and wheel) is a prototype tire designed by Michelin. The tire uses no air and is therefore unable to burst or become flat. Instead, flexible polyurethane spokes are used to support an outer rim. Certain handling gains have been cited as a reason to adopt this type of motor vehicle tire. If certain problems with the prototypes (such as excess vibration and noise at higher speed) are worked out, the first applications for the tire may be in the military where a flat-proof tire would be extremely advantageous to maneuvering vehicles in difficult or dangerous areas. The tweel may eventually be able to outperform conventional tires since it can be designed to have high lateral strength (for better handling) without a loss in comfort.