Pipercross filters are constructed of a multi-stage filter design. Stage 1 is the coarse foam layer that stops larger debris from clogging up the stage 2 filter layer. Stage 2 is the fine pore foam to collect smaller particle that the stage 1 layer missed. In essence, the finer layer of foam stops the fine particles from entering the combustion chamber, where the coarser layer of foam acts as a dust/dirt trap. Restricted airflow only starts when too many of the millions of tiny “routes through the strands” becomes blocked (think of your arteries and cholesterol versus a blood clot).
This is also why the race spec filter works so well. Instead of simply having “more/larger holes in a screen” which results in depleted particle capture, the race filter simply has less/thinner coarse dust trap foam. So the filter offers an overall higher level of airflow, but for a shorter amount of time before more of the particles are filling the space between strands and lowering flow efficiency. This IS NOT POSSIBLE with cotton gauze filters, of any brand.
Schnitz Racing has a full line of Pipercross Air Filters available for all popular Superbikes.