The Vittoria Air-Liner MTB Tyre Insert is a foam-based tubular insert for tubeless tires designed to protect the rim, enhance grip and prevent punctures. It is made up by a new-generation polymer, and the entire tube comes through coring process. Differently from printing and extrusion – cheaper production processes used for equivalent products available in the market – coring does not alter the chemical structure of the polymer. As a matter of fact, the added value of Air-Liner lays in its high-quality production process. Air-Liner can be used on both standard wheels and tubeless-ready wheels, with both tubeless and tubeless-ready tires, and with any type of sealant – preferably without ammonia. In addition, it fits any type of valve for tubeless. Although Air-Liner polymer is slightly dense, it is very resistant. This particular structure provides the insert with light weight without compromising on resistance and duration: Air-Liner weight goes from 160 g to 220 g according to the size, and the product life cycle is 2,000 hours in normal conditions or one-hour run flat – calculation based on a rider of 80 kg of weight. Vittoria Air-Liner MTB Tyre Insert Specification Size S – Cross-Country / Marathon – from 1.9” to 2.2” Size M – All Mountain / Enduro – from 2.25” to 2.5” Size L – Enduro / Plus – from 2.5” to 2.7” Size XL – Plus / Fat – from 2.7” to 4.0” Vittoria Air-Liner MTB Tyre Insert Features More grip, in both climbing and descent Enhanced rim protection Allows for lower tire pressures Prevents burping effect Prevents bead breaking Absorbs high-frequence vibrations. Comfort increased. Allows for tires with lighter casing Air-Liner comes as a tube with two continuous carvings – one at the top and one at the bottom of the tube – designed to make room for the air and sealant within, and to better support the tire.  In the packaging, Air-liner comes with a zip tie to close the tube on the rim. As the Air-Liner length always exceeds the wheel diameter, you need to cut the edges of the tube according to the size of the rim (you can use a cutter for this processes). After that, you need to make two holes – one for each extremity of the tube – and insert the zip tie in the two through holes (you can use a screwdriver for making the holes). Apart from this process, the mounting of the Air-Liner is not too different from the one of inner tubes. To facilitate the mounting even more, we suggest lubricating the insert with some water.