The foam of Air-Liner Road is soft and is designed to collapse inside the pressure of a road tire. That allows for the expansion of the foam in the event of a flat tire. In fact, the foam fills the volume inside the tire and allow for a run-flat solution to get you home Features: Enhanced rim and tire protection, allows for lower tire pressures, and run-flat capability to always get you back home Designed to be used with sealant - preferably without ammonia Air-Liner Road increases the safety of tubeless-ready tires by locking the bead of the tire into the rim, reducing the likelihood of burping at the bead Features a complete hoop as well as a hexagonal cross-section shape, both of which are designed to lock into a 700c road wheel and provide a very positive bead lock on tubeless tires