Schwalbe standard bicycle inner tube no. 7B. For bicycle and wheelchair tires in size 20" inch (ETRTO 23/25-451). Holds air longer than average. Thanks to the best material quality and uniform wall thickness. Maximum reliability proven millions of times over. Product Description Inner tube for 20" tyres. Specifications:Application:City & TouringETRTO:23-451 to 25-451Tyre Dimensions:20 x 0.9" to 20 x 1.0"Inner Tube Material:butylValve Type:AV / Schrader 40 mm, SV / Presta 40 mmDimensions (ETRTO):20 x 0.90 (23-451)20 x 1.00 (25-451)Models:20x0.9-1.0 AV / Schrader 40 mm Valve Type:AV (Auto / Schrader valve)Valve Length:40 mmType:AV7BManufacturer Number:10416290 20x0.9-1.0 SV / Presta 40 mm Valve Type:SV (Sclaverand/Presta)Valve Length:40 mmType:SV7BManufacturer Number:10400013Valve InformationTubes are available with various valve types. Choosing a valve is dependent on application and the rim's valve hole diameter. AV / Schrader Valve: Synonyms: Auto Valve (AV), Schrader ValveOuter Diameter: 8.5 mm SV / Presta Valve: Synonyms: Sclaverand Valve (SV), French Valve, Presta ValveOuter Diameter: 6.5 mmOther: all Schwalbe tubes with a Presta valve can be unscrewed. (To lengthen the valve, add anti-flat agents, etc.)Technology:Inflation Pressure Stability A Schwalbe inner tube maintains the air much longer. The quality of the inner tube is already determined by its raw materials, through the ingredients and the purity of the rubber compound. During vulcanisation, each Schwalbe inner tube is placed in a mould and is then inflated. This is the only way to ensure a uniform wall thickness and excellent air retention. Reliability Rigorous monitoring that ensures the best operational reliability: each inner tube is inflated in the fabric and stored under pressure for 24 hours to check the air retention ability. Tube Groups System Due to its high elasticity and quality, a single inner tube covers a large number of tyre sizes. For example, inner tube no. 17 works just as well for 28 mm wide tyres as for 47 mm wide tyres. Only an extremely high-quality and reliable inner tube can meet this requirement. Contents:1 x Schwalbe 7B inner tube Weight: universal | Presta Valve (SV) | 23-451 to 25-451 | 20x0.9-1.0 Presta 40 mm | 40 mm: 85 g Manufacturer: Ralf Bohle GmbH Otto-Hahn-Str. 1 51580 Reichshof Germany info@schwalbe.com