The device includes {TAIL ~ a first subset} of light modulators and a second subset of {HEAD ~ light modulators} 
The device includes { TAIL ~ a first subset } of light modulators and a second subset of { HEAD ~ light modulators }
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD