{HEAD ~ The rail section} has a profile that provides one or more roller contact areas extending {TAIL ~ a length} of the rail section 
{ HEAD ~ The rail section } has a profile that provides one or more roller contact areas extending { TAIL ~ a length } of the rail section
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH