The second main body and the second lens portion are made of {HEAD ~ a same polymer material} having a lower melting point and {TAIL ~ higher fluidity} than polyether imide 
having
The second main body and the second lens portion are made of { HEAD ~ a same polymer material } having a lower melting point and { TAIL ~ higher fluidity } than polyether imide
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH