The shaft is connected to a movable vent follower located at {HEAD ~ the interface} between {TAIL ~ the cells} 
between
The shaft is connected to a movable vent follower located at { HEAD ~ the interface } between { TAIL ~ the cells }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL