The Tubo-CX/Gravel is twice as robust as standard tubes. And at the same time, due to its low weight of 60 grams, it guarantees twinkle toed rides. The 50% smaller packed size makes it also a spare tube which fits in every pocket. Designed for disc and rim brakes. Specifications - Labeled Size: 700 x 30-40 - ISO Width (mm): 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 - ISO Diameter: 622 / Road / 29" - Shaft Type: Smooth - Valve: Presta Med 41-55mm - Tube Compound: Thermoplastic Elastomer