Michelin a4 airstop 29 mtb tubethe michelin airstop butyl range of inner tubes fulfills the needs of everyday cyclists for an economical high quality inner tube it features good puncture resistance and an excellent value for the money thats backed up by the impeccable reputation of michelin type a4 identifies the inner tubes for 29 tires with a width up to 54mm featurespresta valve also known as sclaverand or french valve dunlop valve woods bicycle english or dutch valve schrader valv