This is a product I personally requested and helped design!

 

I don't know about you, but I store my DPNs in a small jar and carry several sets around in a zippered pencil case. As you know, not all DPNs are labelled, so it's sometimes difficult to determine which set is the one you need for a project. I asked Karen of Karatstix to create for me a thin 6" ruler, with gauge holes in it to keep right with my DPNs. I now have one in my jar and another in my pencil case.

 

This is a heavy-duty, no-frills item that travels well. And better than many commercial varieties, it goes all the way down to a size US 0000!