Such flexibility is important for adjusting the amount of {HEAD ~ light} entering through {TAIL ~ the panel} according to the ambient lighting of the external environment, which would differ during daylight hours as opposed to the night, for example 
entering through
Such flexibility is important for adjusting the amount of { HEAD ~ light } entering through { TAIL ~ the panel } according to the ambient lighting of the external environment , which would differ during daylight hours as opposed to the night , for example
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH