Developed in collaboration with Deaneasy, the Vittoria Air-Liner MTB Tire Insert is the ultimate tire accessory for mountain bike tires. This innovative foam-based tubular insert for tubeless tires is a breeze to install, and does its job exceptionally well of protecting the rim, enhancing overall grip, and preventing punctures on some of the roughest and rowdiest trails. Made from a new-generation polymer, the technical foam Air-Liner allows for lower tire pressures, prevents burping and bead-breaking, and and absorbs high-frequency vibrations for a smoother ride. While this polymer is slightly dense, it more than makes up for extra weight with incredible resistance to rocks and trail debris. Two continuous carvings-one on the top and one on the bottom-run the length of the Air-Liner to make room for the air and sealant within, and to better support the tire. Plus, installation is exceptionally easy thanks to the included zip ties and smooth cut-ability of the foam.