Rather, the flow hole 250 maybe implemented as any suitable flowpath connecting {HEAD ~ the two filters} 218,220, including, for example, a rubber or reinforced hose or elongated channel or {TAIL ~ ductwork} 
including
Rather , the flow hole 250 maybe implemented as any suitable flowpath connecting { HEAD ~ the two filters } 218,220 , including , for example , a rubber or reinforced hose or elongated channel or { TAIL ~ ductwork }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL