This sale is for two ferro rods, they are 1/2" diameter and 4" long with drilled lanyard holes. Scrape ferro rod with a piece of hard steel that has a 90 degree sharp edge, not smooth, and it will create hot sparks.The striker that you use makes a difference, practice with different strikers for best results. Focus the sparks at your favorite tinder and it will catch on fire. Check my other listings for the best strikers for your ferrocerium rod.