"Excellence in Performance", backed by the best one-year warranty in the industry! Modified Sprung Street Disc Smooth engagement, quick shifts, OE to mild gear rattle; Premium organic friction materials for heat tolerance, faster recovery from overheating and prevents warping of mating surfaces; Spring retainers feature heat-treated wraparound spring windows that provide support and reduce stress concentrations that are common causes for failure; Recommended for street and occasional race use; Steel-backed linings for higher burst strength, reduced marcel for quicker shifts 2001403 is a modified spring-centered street disc featuring premium organic friction material with high copper content for better heat transfer and steel-backed lining for greater burst strength and durability. These discs are modified with reduced marcel for faster shift action to complement ACT pressure plates. The heavy duty torsional dampening springs are stronger, in most cases, than standard springs and are provided in the best sizes and spring rates to suit the application. Modified street discs allow for quicker shifting and engagement. Quiet operation with increased strength and reliability.