These tubes fit all the 650B tires we sell perfectly and will also fit 650A tires in the 35-43mm width range. A printing mistake on the box says these are 650C tubes, but pay it no mind. Presta valve only. If you’ve drilled your 650B rims out for Schraeder valves, get our 650A tubes, which are Schraeder only. The minute (6mm) difference in the bead seat diameter between 650A and 650B tubes means they can be used interchangeably (the tires cannot), so if you’re using 650A wheels with rims drilled for a presta valve, you should buy the tubes on this page.