The Schwalbe Tube 7S is a reliable standard inner tube for 20-inch bicycle tires. Thanks to its high-quality butyl rubber compound and uniform wall thickness, this inner tube holds air for an above-average duration. The proven Schwalbe quality guarantees maximum reliability, as demonstrated millions of times in practice. Specifications: Brand: Schwalbe Model: Tube 7S Inner tube type: Standard Material: Butyl Wheel size (inch): 20 ETRTO: 28/37-438 / 28/37-440 / 28/37-451 Valve type: AV (Auto) Valve length: 40 mm Weight: 105 g Schwalbe standard bicycle inner tube no. 7 S. For bicycle tires in size 20" inch (ETRTO 28/37-438/451). Holds air for an above-average duration. Thanks to the best material quality and uniform wall thickness. Maximum reliability proven millions of times over.