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