{HEAD ~ A ring} is rotatably mounted to {TAIL ~ the cylindrical top} and has three notches defined in an inner periphery thereof 
{ HEAD ~ A ring } is rotatably mounted to { TAIL ~ the cylindrical top } and has three notches defined in an inner periphery thereof
HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH