Finally, the protective coating 13 is applied to {HEAD ~ the surface} of the filter as the last layer, and once again the peripheral region is kept free in {TAIL ~ order} to form the contact bank 8 
Finally , the protective coating 13 is applied to { HEAD ~ the surface } of the filter as the last layer , and once again the peripheral region is kept free in { TAIL ~ order } to form the contact bank 8
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH