Oval fire steel - based on originals found at archeological sites throughout North America, especially the Great Lakes Fur Trade area. This style has been listed in trade goods lists from the mid 1700's through the mid 1800's, but the oval style has been around since early Roman times. Examples are pictured and described in the books Where Two Worlds Meet, Voices From The Rapids, Firearms Traps and Tools of the Mountainmen, A Toast To The Fur Trade, and several issues of The Museum of the Fur Trade Quarterly. This fire steel measures 3 1/2" by 1 1/2" by 1/8th inch thick - per the dimensions listed in Where Two Worlds Meet. Yes, many of the originals were only 1/8th inch thick, 1/16th inch thick, or THINNER.