Marking pin and marking head designed by ourr technical  which is much different than other brand.
The desig  and  let the machine marking more beautiful.
There are four different size,3*11,3*16,5*16,5*20.   3*11 is widely used. 3*16 is  mostly use for protable marking machine.
If yuou have some special requries to marking very deep, so you can choose 5*20