![Schwalbe Inner Tube AV21 - 27.5 x 1.50 - 2.40" (650B) Schrader Tube - 40mm](http://senacrecycles.co.uk/cdn/shop/products/p5c7029a71f9466.30645139_4251aa3e-fa51-46e7-b515-a0dd8b3cc900.jpg?v=1705159238&width=1445)
- Extremely airtight! The Butyl rubber compound prevents pressure loss and fewer occassions to inflate. Extremely reliable! Quality control for safer cycling: Each tube is checked twice at the factory to ensure safer cycling. Having the correct pressure means fewer punctures and reduced rolling resistance