In at least one example, the base has polygonal guide holes through which {HEAD ~ the stems} extend from {TAIL ~ the base} in the extended positions 
In at least one example , the base has polygonal guide holes through which { HEAD ~ the stems } extend from { TAIL ~ the base } in the extended positions
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH