Each one of {TAIL ~ the two or more individual endless belts} of {HEAD ~ each unit} is made of a relatively soft and elastic material, or is padded or covered with foil material, such as latex 
Each one of { TAIL ~ the two or more individual endless belts } of { HEAD ~ each unit } is made of a relatively soft and elastic material , or is padded or covered with foil material , such as latex
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH