The runner is accommodated at the fixing portion, and is capable of {HEAD ~ up and down sliding movements} at {TAIL ~ the fixing portion} 
at
The runner is accommodated at the fixing portion , and is capable of { HEAD ~ up and down sliding movements } at { TAIL ~ the fixing portion }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL