Schwalbe SV21/AV21 - 27.5 x 1.50 - 2.40" (650B) Schrader or Presta Inner Tube
Extremely airtight! The Butyl rubber compound prevents pressure loss and fewer occasions 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
Not a lot to say really decent quality innertube, does what its supposed to.
Very good quality inner tubes. come with better dust caps than other brands I have bought. Paired with the Schwalbe marathon plus MTB tyres on my E bike hope to reduce the risk of punctures. Like the fact these are designed to be less porous and so retain air for longer.