The U.S. General Services Administration (GSA) has awarded a five-year contract to Sun-Tech Innovations for its Balance Masters self-adjusting wheel-balancing system. The system will be used on vehicles owned by the Department of Defense and other government agencies. The Balance Masters system uses fluid mercury to compensate for out-of-balance conditions and vibrations in tires. The patented system, according to the manufacturer, eliminates wear patterns and only requires a single installation.