First flat in a long time today. A piece of glass the size and shape of an arrowhead went straight through the middle of the tread. I don't think any tire could have prevented this one. I am perplexed at how it could have happened. The sliver was almost 2 inches long and about 3/4" wide at the base, and the glass was pretty thick. The only thing I can imagine was that the chunk was somehow sitting point up in a crack in the pavement or something.