Manufactured with a thermoplastic elastomer, called TPU. These tubes are lighter, and more robust than traditional butyl rubber inner tubes Even lighter and more compact - due to a removable valve S-Tubo-MTB&&';;s can be rolled up to an extremely space saving size (3.5 x 5 cm) Despite a light overall weight of only 43g they are as puncture resistant as standard rubber tubes for everyday riding Also perfect for use as a spare tube for riders using a tubeless system Ready for disc brakes only Labeled Size: 27.5"/29 x 1.8 - 2.5" Shaft Type: Threaded Tube Compound: Thermoplastic Elastomer ISO Diameter: 584/622 / Mountain / 27.5"/29" Valve: Presta Med 42mm Weight: 43g.