SmarTUBE X: Maximum robustness and puncture resistance, for an urban, gravel or e-bike use. The Pirelli SmarTUBE inner tube family is made of thermoplastic polyurethane TPU) that is a characterised by high elasticity and mechanical resistance, and extreme lightness. Pirelli SmarTUBE X TPU inner tubes are designed for use with the Pirelli CINTURATO and ANGEL tyre families: three times thicker than the first generation CINTURATO SmarTUBE, the SmarTUBE X offers an increased level robustness and puncture resistance. It is particularly suitable in city settings or for fast commuting, where their speed and reliability characteristics are highly valued. The SmarTUBE X tubes, in line with Pirellis TPU inner tube family, are extremely compact: -50% space taken up in a jerseys pockets or in the backpack, and up to 70% lighter compared to the traditional butyl inner tubes, these TPU inner tubes make for an excellent space saving back up to carry on longer rides. SmarTUBE X tubes come in a range