In one example, a core cover includes an inner wall that defines a fluid passageway configured to communicate with an interior of a filter core when the core cover is engaged with the filter core. As well, the core cover includes an outer wall spaced apart from the inner wall, and a complementary structure located on the outer wall and configured to engage a corresponding complementary structure of a filter core. Finally, the core cover includes one or more indicia that indicate a flow rate, or range of flow rates, associated with the core cover.