a plurality of independently mounted rollers fixably and detachably mounted to {HEAD ~ said first members} of {TAIL ~ said frame} such that said rollers vertically extend above said frame; and, 
of
a plurality of independently mounted rollers fixably and detachably mounted to { HEAD ~ said first members } of { TAIL ~ said frame } such that said rollers vertically extend above said frame ; and ,
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH