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