These are cone filter inserts for any plastic funnel to help remove any sediment that builds up in your bottles of Pretreatment or ink. These are 200 micron mesh filters that do a great job filtering either suspect pretreatment and ink or pretreatment that has been sitting a while. Any smaller micron and it would take you forever to filter. This is the perfect micron level so that you don't strip white ink of the Titanium or strip the components of the pretreament.