Filter panels are removably attached to the outer surfaces of the edges and {HEAD ~ filter material} is mounted in the panels to cover {TAIL ~ the empty spaces} 
Filter panels are removably attached to the outer surfaces of the edges and { HEAD ~ filter material } is mounted in the panels to cover { TAIL ~ the empty spaces }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL