In Pozen Inc. v. Par Pharmaceutical, Inc., 696 F.3d 1151 (Fed. Cir. 2012), the Federal Circuit addressed the application of the doctrine of equivalents to ‘fuzzy’ claim limitations – i.e., claim limitations without set boundaries. The Federal Circuit found that even when the District Court has construed such limitations to have a definite meaning, the application of the doctrine of equivalents is not precluded. This case report presents the arguments made to the Federal Circuit by the parties and how the Federal Circuit addressed these issues.