Filter with retained safety element

A filter (10) has a housing (12) extending along an axis (18) between first and second axial ends (20 and 22), and has a closed loop primary filter element (24) extending axially in the housing, and a closed loop safety filter element (48) in the hollow interior (30) of the primary filter element. A detent member (60) engages and retains the end cap (54) of the safety filter element independently of the primary filter element to retain the safety filter element in housing upon removal of the primary filter element from the housing.