As mentioned above, the distance between {TAIL ~ the brush members} arranged in {HEAD ~ series} can vary 
As mentioned above , the distance between { TAIL ~ the brush members } arranged in { HEAD ~ series } can vary
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH