Tufo Tire Sealant is your best protection against flatting your tubular tires. If you cut your tire while you're riding down the road the sealant immediately plugs up the hole. Countless cyclists count on it, and they ride their tubulars in peace thanks to the security they get from the sealant. You simply unthread the valve on your Tufo tubular tire and pour in a few tablespoons of sealant. In order to unthread the valve, you need this handy little tool.