The time consuming part is cleaning, the measuring and cutting take a minutes tops, all you need a metal ruler, a sharp blade, and a steady hand. Most seal widths range between 2mm (most surrounding door/body seals) and 5-6mm (most door hinge seals) in width. Working with your multiple cameras its easy to slice up a few long lengths (that run the entire length of the foam piece) of each, then individually part them out to the required lengths as you go down the list of cameras.