Not necessarily the best way to repair a tire, but one that will get you to the next town or to a shady/protected area to do it right. Works by filling the tire with a foaming latex-like fluid that seals the hole, and will fill a tire to moderate pressure in around 20 seconds. (Bear in mind, however, that when you remove the tire for permanent repairs, it’s gonna be full of this stuff. We warned you.) Tire pressure will increase gradually as you ride. Will not work on large holes or sidewall punctures. Attached fill hose.