You can estimate the approximate amount of filament required within most slicing programs. However, the estimate will vary depending on which slicer was used, and what print settings were applied. If it helps, I used Simplify3D to slice both the Filter_v2.STL and Box_v2.STL.
Printing the "box" piece at .2mm layer height, with the suggested infill of 10% with a honeycomb pattern rotated at 45°, with 3 perimeters (vertical walls), with 5 solid top and bottom layers: 66.37 grams
Printing the "filter" piece using the same settings as above, but with 0% infill: 18.57 grams
Estimated Total: 84.94 grams (let's call it 85 grams)
Again, these numbers are just an estimate and will vary greatly with different print settings and slicers. The final actual weight of the parts will depend on these variables, as well as the printer hardware used. I hope that at least helps give you a general idea. Cheers!