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