A filter including a filter bowl (4), filer head (48) and filter element (2). The filter element (2) comprises a locking ring (12), a first end cap (6) coupled to the locking ring (12), a filter media (10) coupled to the first end cap (6), and a locking rib (30) extending outwardly from the locking ring (12). The locking rib (30) comprises a first portion (34) which extends radially from the locking ring (12) and a second portion (38) which extends from the first portion (34) around the periphery of the locking ring (12). At least part of the second portion (38) of the locking rib (30) is arranged to flex relative to the first portion (34) of the locking rib (30). The locking rib (30) forms part of a bayonet connection.