Need help identifying year of Ultegra rear derailleur I am helping a friend sell triathlon bike (he recently bought a mountain bike and does not need to have more bikes sitting around), and so I am trying to gather more information around the bike to provide as many details as possible to potential buyers. It's a 2009 orbea Aletta. He's got a FSA front derailleur and Shimano 105 shifters (he converted the tri bike into a roadie). According to the BBB, it does not look like the bike is worth a whole lot, but it is better than nothing! 
If anyone has any clue, I would greatly appreciate it. Thanks!
I believe that is an Ultegra 6600, made from 2005 to 2008 (according to Wikipedia). Not sure you will be able to narrow it down to the exact year.