Scott W. Schwartz, Cottage Grove, WI (US)
Robert A. Bannister, Ames, IA (US)
Joel D. Roltgen, DeForest, WI (US)
Jeffrey A. Rech, Verona, WI (US)
Stephen L. Fallon, Oregon, WI (US)
Gregory K. Loken, Stoughton, WI (US)
1. A filter element, comprising:a filter media formed in a closed loop, the closed loop defining a hollow interior extending along a longitudinal axis between a first end of the filter media and a second end of the filter media; and
an outer surface surrounding a perimeter of the filter element, the outer surface defined by a substantially circular first portion and at least one second portion, the first portion being substantially circular at a selected height of the filter media, the at least one second portion being depressed relative to a circle defined by the substantially circular first portion at the selected height, the at least one second portion being substantially flat and extending between circumferential ends of the first portion.