Continental Lightweight Presta tubes. Seamless and mold cured construction. Removable valve core. Presta and Schrader have removable valve cores. Presta and Schrader valves are threaded full length. Weight: 65. Valve: Presta Med 41-55mm. ISO Diameter: 571 / 650c. ISO Width: 18. ISO Width: 19. ISO Width: 20. ISO Width: 21. ISO Width: 22. ISO Width: 23. ISO Width: 24. ISO Width: 25. Labeled Size: 650 x 18-25. Tube Compound: Butyl. Valve Core: Removable. Presta Shaft TYPE: Threaded.