The filter body is designed with a propeller shape and has two blades connected by {HEAD ~ an axle} of {TAIL ~ the filter} 
of
The filter body is designed with a propeller shape and has two blades connected by { HEAD ~ an axle } of { TAIL ~ the filter }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL