Thick U2 Black Back for iPod Classics. You can use this with iPod Video 5/5.5, and iPod Classic 6/7 Gens. Brand New! This is a thick back, so please make sure your model is compatible for this. Example: Originally, the 5th gen 60/80GB had thick backs, and the classic 6th 160GB (the black and silver front, not charcoal one) were thick models.