FrontLine Blue fiberglass rolls contain commercial grade media for medium to heavy dirt loading conditions. The high fiber content of the media provides more dirt catching surface, while its progressive density pattern prevents faceloading. Dirt loads from back to front, taking advantage of the entire thickness of the media for increased arrestance and dust holding capacity.

In this FrontLine model, each fiber intersection is solidly bonded with cured resin to increase compression strength. These bonded fibers create a barrier against dirt and improve filter performance by preventing particles from passing through the media. The medium application of Viscosine adhesive helps further retain particles to prevent them from flowing downstream (blue dry rolls are also available).