The Schwalbe No.13 is an MTB inner tube with Dunlop valve. The butyl rubber tube is extremely airtight and elastic. The high elasticity means the tube covers a wide range of tire sizes.
The Schwalbe No.13 fits the following tire sizes:
40-559 (26 x 1.50)
47-559 (26 x 1.75)
50-559 (26 x 2.00)
54-559 (26 x 2.10)
57-559 (26 x 2.25)
60-559 (26 x 2.35)
62-559 (26 x 2.50) ;