A temple endpiece includes {TAIL ~ a set} of recesses that engage the projections formed on {HEAD ~ the lens} 
A temple endpiece includes { TAIL ~ a set } of recesses that engage the projections formed on { HEAD ~ the lens }
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD