Insert doesn't crumble and it has no expiration date Punctures have no effect on tire pressure and you can readily ride across razor sharp glass without losing tire pressure. Specifically designed for minicross High elasticity, it adapts to any type of tire, managing to 100% fill the casing Mousse eliminates flats. instead of air inflating the tire, a foam insert replaces the air and expands the tire. 70/100-19 has cut line on insert to fit 70/100-17 as well