The scrubber drum includes at least two sections {TAIL ~ each} of which has {HEAD ~ a polygonal shaped, water tight interior chamber} 
The scrubber drum includes at least two sections { TAIL ~ each } of which has { HEAD ~ a polygonal shaped , water tight interior chamber }
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD