The design of the double-coiled fire striker is based on historical models from the Middle Ages, particularly the so-called two-armed steels or Alemannic models. To generate sparks, the hard edge of the carbon-rich steel is struck against a flint in a striking motion. The friction scrapes off tiny metal particles, which instantly ignite in the air, producing sparks up to 1500 degrees Celsius, which are then dropped onto prepared tinder.