Since the invention of the air-filled tire by John Dunlop in 1888, the bicycle tube has kept the air in the tire. Fischer tubes are made from durable and flexible rubber. Tubes form the basis of relaxed cycling: if the tube fits perfectly on the rim and forms an optimal unit with the tire when properly inflated, it rolls almost by itself. Of course, the elastic tube can also be stretched a bit to fit a larger rim or compressed to fit a smaller rim, but both options can affect the riding behavior and the lifespan of the material. Therefore, it is important to purchase exactly the type required by the rim, including the correct valve for the existing hole. ETRTO standards: 37-622, 40-622, 42-622, 44-622, 45-622. Inches: 28 x 1.35, 28 x 1 5/8 x 1 3/8, 28 x 1.4, 28 x 1.5, 28 x 1 5/8 x 1 1/2, 28 x 1.6, 28 x 1.625, 28 x 1.75. The elastic material covers all the mentioned tire sizes.