can 2600 filter setup help needed

I just got a can 2600 filter and a 95cfm fan combo, the filter came with a 4"flange what I dont get is how to attach the filter to the flange, the flange is just a round piece of steel that fits down on top of the filter, the flange came with 4 screws and some 1/4 foam with 1 side sticky, but there are no screw holes in either the flange or filter, am I just supposed to cut some holes in the flande and screw them directly into the top of the filter through there are no holes?

Any help with this would be greatly appreciated sent email to the place I got everything but no reply yet

my guess is that the foam is to go inbetween the flange and filter to seal it, so you can screw the flange onto the filter and still have it air tight.