Just when you think things can"t get any better in the line of high performance clincher tires. Continental raises the bar again with the GP4000. Predecessor to the GP3000, the GP4000 introduces a host of innovations which include:20% less rolling resistance. Lightweight at just 205 grams for a 700 x 23C. Vectran puncture protection. Higher mileage. Anti-aging compound.Tread wear indicators.