After selecting your knife it's now time to look through pins and handle materials.  Here you'll find three metal tube pins.  They are 1/4" in size.  You get (2) two per knife.  If you wish to add one of these to a knife as a lanyard tube and to accompany other pins, simply choose the pin you like and add it to cart.  I'll see that you are adding one of these to your order and will know what it is for.