I never know since the term "hone" gets used for stones and rods by customers. In this case I was wrong. He wanted a rod.
So, for a good rod try the Idahone:http://www.chefknivestogo.com/id12cerodwna.html
I like these because they are pretty fine, gentle on the edges and still remove a small bit of material each time you use it. Hard and smooth is best for higher hardness knives.