A ferro rod option is a great way to ensure you always havea  way to start a fire! 
 
The ferro rods I use are made in America and made by the same company that supplies our service members and other armed forces around the globe.  They are 3/8" diameter and start out at 4" in length.  The completed ferro rod is a bit longer of course because of the handle materials that are used. 
 
You have a few options when it comes to handles.  Sometimes I can match the materials used on your knife and others I use antler or a contrasting material to go with your knife scales selection.  Remember, when in doubt, feel free to email me to ask questions as to the best way to proceed.
 
If you have a knife and sheath already and want a ferro rod attached to your existing set-up, I will need you to package and ship to me.