iPod classic 7th generation. 

Browsing eBay and wanted information relating to the difference between them. I couldn't find anything in this article about 7th generation iPod classics.
http://www.thestudentroom.co.uk/showthread.php?t=609816 

^ forum discussion about the difference. 

Apparently ehow is blocked, but for a source of information between differences of 6/7 go to the main website and insert '/about_6323160_difference-6th-generation-7th-generation.html'