Were not afraid to say itour Airlock Presta Valve Tubes are the best performing, self-sealing bicycle tubes available. Thats because they feature our powerful Airlock sealant that coats the tube for permanent protection against punctures. Not only this, but the sealant is designed to work continuously in order to prevent slow leaks from occurring, so erring complete catastrophe, you wont have to worry about flatting when youre riding over debris. We even addressed the common issue of sealant pooling with a completely homogenous design, so the tire/tube combo will always roll smooth and even.