Continental Mtb 275 X 175-25 Mountain Bike Inner Tubes With Presta Valve (Pair)continental MTB 275 x 175-25 Mountain Bike Inner Tubes with Presta Valve Butyl tubes with the excellent continental quality Seamless construction, with a mould-cured vulcanisation to ensure uniform roundness and to give a smooth ride and handling Features: 275 (650B) Mou..