Th most underrated product out there. Every tool bag should have these. Cut them in half, in fourths. I can't tell you how many people ask me for a tire boot on longer, dirt, gravel rides. When your sidewalls wear out, when you get a big shard of glass that puts a big hole in your tire, this is what lets you ride home instead of walking or calling for help. Essential.
Even a small cut in the tire can leave you walking home if you have no way of containing the new or patched tube inside the damaged tire. Sure you can use the old dollar bill repair, or look for some leafs or scrap paper. These tire boots are the way to go, easy to use, they stick in place and there are 3 in the set to share with friends.
Used it in Iraq riding on some awful roads. With no desire to be broken down any longer then need be, i used this system twice to get up and out of an area that was not overwhelmed with joy to have me hanging around, all and all I was back on the road in less then ten minutes. great fast fix, light weight and easy to use.