These Continental MTB 27.5 inner tubes are ideal replacements or spares for when the inevitable puncture happens. Made from Butyl rubber, these tubes fit 650b (27.5 inch) MTB wheels. Continental MTB cycling tubes are available in Schrader or Presta valve options, all made with a seamless construction and uniform roundness. Ideal to get you back up and riding in no time. Key Features Butyl rubber mountain bike tubeFor 27.5" MTB tyresSchrader or Presta valveAll tubes have a seamless construction, with a mould-cured vulcanisation, to ensure uniform roundness