Air-Liner GRAVEL is an insert for tubeless-ready gravel tires. Re-usable and very easy to install--as easy as mounting an inner tube on your tire--Air-Liner GRAVEL is compatible with tubeless-ready tires only and with 3-way valves (5-way valves are included for ultimate airflow). The insert can be used with sealant--preferably sealants without ammonia. - Air-Liner increases control, durability, performance, and protection of both tire and wheel. - Compatible with any wheel size up to 700c with 3-way tubeless valve, and tire widths from 31mm to 40mm. - The Vittoria Air-Liner is a tire insert, designed for use in tubeless tires. - Sold individually (single tire).