{HEAD ~ The rollers} can be moved apart to allow {TAIL ~ the snake} to be initially mounted in the machine 
{ HEAD ~ The rollers } can be moved apart to allow { TAIL ~ the snake } to be initially mounted in the machine
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH