A secondary filter element comprising: (a) a first wall of media extending between a closed end cap and an opposite open end cap, the first wall and end caps defining an interior volume, the open end cap defining a sealing structure; (b) an internal liner adjacent to the first wall of media and within the interior volume defined by the first wall of media, wherein the sealing structure includes a first portion extending into the interior volume along an interior side of the first wall of filter media, a second portion, and a third portion extending over an end portion and over an exterior side of the first wall of media, the third portion being configured to form a radial seal; and (c) an inset collar being disposed within the interior volume, wherein the inset collar extends into the interior volume towards the closed end cap further than the first portion of the sealing structure to fully cover the sealing structure first portion, wherein the inset collar has a length greater than a length of the first portion of the sealing structure, the inset collar being provided with a plurality of radially spaced ribs (1223, 1223'); and (i) the inset collar being provided with a plurality of radially spaced tabs configured to engage with the sealing structure such that the sealing structure may be molded and secured onto the inset collar; or (ii) the inset collar being provided with a singular flange configured to engage with a top surface of the sealing structure such that the inset collar may be properly received into the sealing structure. (a) a first wall of media extending between a closed end cap and an opposite open end cap, the first wall and end caps defining an interior volume, the open end cap defining a sealing structure; (b) an internal liner adjacent to the first wall of media and within the interior volume defined by the first wall of media, wherein the sealing structure includes a first portion extending into the interior volume along an interior side of the first wall of filter media, a second portion, and a third portion extending over an end portion and over an exterior side of the first wall of media, the third portion being configured to form a radial seal; and (c) an inset collar being disposed within the interior volume, wherein the inset collar extends into the interior volume towards the closed end cap further than the first portion of the sealing structure to fully cover the sealing structure first portion, wherein the inset collar has a length greater than a length of the first portion of the sealing structure, the inset collar being provided with a plurality of radially spaced ribs (1223, 1223'); and (i) the inset collar being provided with a plurality of radially spaced tabs configured to engage with the sealing structure such that the sealing structure may be molded and secured onto the inset collar; or (ii) the inset collar being provided with a singular flange configured to engage with a top surface of the sealing structure such that the inset collar may be properly received into the sealing structure. (i) the inset collar being provided with a plurality of radially spaced tabs configured to engage with the sealing structure such that the sealing structure may be molded and secured onto the inset collar; or (ii) the inset collar being provided with a singular flange configured to engage with a top surface of the sealing structure such that the inset collar may be properly received into the sealing structure.