Schwalbe Bicycle Tubes are designed for outstanding reliability. The base material is sieved at enormous pressure through seven filters before being extruded. All tubes are inserted into a mould and inflated for vulcanization to ensure constant wall thickness and high air pressure retention.All valves are nickel plated and threaded and valve inserts are replaceable. Also Schwalbe tubes with the classic bicycle valve are capable of pressure testing.Each tube is crowned with a transparent polycarbonate dust cap.