This kit makes tire repair pretty easy and even kind of fun.
I had opportunity to use mine on a ride a summer ago when I came across a rider with a flat rear tire. The kit worked as advertised. You used the serrated tool to clean and roughen up the puncture, and then you goop up the repair material and force it into the hole. Give the goop a few minutes to set, trim the plug flush, and use the CO2 cartridges to inflate the tire enough to get you to the nearest filling station.
[The manufacturer's site offers many different packages for bicycles, motorcycles, and motor sports.]