I have a set of 716 ap2 irons, purchased new from my club. I want to purchase a back up/travel set. On the internet, I found a set, but do not know how to determine whether they are knock offs. Each of the irons in this set has the same nine digit serial number--seven digits, a space a two more digits. My set has a seven digit serial number.
Any tips on determining whether these are legitimate Titleist clubs?