Yesterday, in a precedential opinion the Third Circuit continued its limitation of the ascertainability requirement as applied to consumer class actions. The Circuit’s opinion in City Select is important as it not only limits the broad application of ascertainability as applied by some Courts, it also reflects that Defendants arguing that a class is not ascertainable should be required to turn over information in its possession about potential class members prior to the certification of a putative class. Importantly the Circuit also noted that ascertainability did not constitute a per se ban on the use of class members’ affidavits to determine class membership.