| GENERAL CHARACTERISTICS ITEM DESCRIPTION | 1.600 IN. DIA;CENTER THK 0.150 IN.;CENTERING .0005 IN. FIR,1.0 MIN. TIR;EFL 4.213 IN. REF;BFL 4.125 IN. REF;MATL SCHOTT OPTICAL GLASS,TYPE 691547,LAKN9,GRADE A,STAIN 3,ANNEAL FINE,PER MIL-G-174;COATING SLAR 101 |