A tube is not just a tube. Schwalbe tubes retain air pressure considerably longer than other brands. The quality and material purity of the rubber mixture directly impacts the performance of the tube. Each Schwalbe tube is individually inflated and inserted into a mold, resulting in consistent wall thickness and excellent air retention. The high elasticity of the material used allows a great many tire sizes to be covered. For example; the SV17 tube will work in tire sizes 700 x 28 through 700 x 45. Only an extremely high quality and reliable tube is up to this requirement.PRESTA VALVE SV 13 fits 26x1.50, 26x1.75, 26x2.00, 26x2.10, 26x2.25,26x2.35, 26x2.50, 200 grams