Continental Grand Prix 4000S II Tire. Vektran and Black Chili Sounds like some kind of explosive...but the only thing blowing up will be your riding performance. Continental's Grand Prix 4000S II road tires not only sport a layer of Vektran technology to increase puncture protection, but they feature Black Chili carbon particles that reduce rolling resistance, maintain traction, and reduce wear. Add in amazingly supple 3330 tpi sidewalls and you've got a magical tire that's light enough for racing, tough enough for training, all with an exquisite ride quality that will plain amaze on every ride. And the icing on the cake are the sidewall color options so you can raise your bike's aesthetic game to new heights.