The invention is also more efficient and effective because of {HEAD ~ the ease} of {TAIL ~ the filter materials} that may be washed and changed 
of
The invention is also more efficient and effective because of { HEAD ~ the ease } of { TAIL ~ the filter materials } that may be washed and changed
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH