While four rollers are shown, {TAIL ~ the number} and {HEAD ~ size} of the rollers may vary with the type and size of fiber being treated 
While four rollers are shown , { TAIL ~ the number } and { HEAD ~ size } of the rollers may vary with the type and size of fiber being treated
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH