First of all, the pressing roller unit or a plurality of such units is located at {TAIL ~ the appropriate location} or {HEAD ~ locations} 
First of all , the pressing roller unit or a plurality of such units is located at { TAIL ~ the appropriate location } or { HEAD ~ locations }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD