These tools are designed to leave small indicator marks on you leather projects, so that you can then hand sew to a specific number of stitches per inch. Each of our heat treated wheels is mounted in a very highly polished stainless carriage. Overstitch markers NOW- come in five sizes, 4,5,6,7,8 stitches per inch. We have been working our butts off to get the new size 8 ready for you and here it is. If we get enough feed back from you leather workers on the need for a "PRICKING WHEEL STYLE" SERIES OF MARKERS WE WILL CONSIDER IT. So get off yer duff and send an email so that we can serve you better.