Each device 32 is held on {TAIL ~ the fixture} by {HEAD ~ a vacuum} in the headspace above the device 32 
Each device 32 is held on { TAIL ~ the fixture } by { HEAD ~ a vacuum } in the headspace above the device 32
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH