| ELEMENT LEFT SURFACE RADIUS | 1.9405 INCHES AND -1.1957 INCHES |
| ELEMENT RIGHT SURFACE RADIUS | -1.1957 INCHES AND -2.7240 INCHES |
| ABBE CONSTANT | 64.500 AND 33.800 |
| BACK FOCAL LENGTH | 2.491 INCHES |
| AXIAL THICKNESS | 0.3662 INCHES NOMINAL AND 0.0866 INCHES NOMINAL |
| COMPOUND LENS EDGE THICKNESS | 0.281 INCHES NOMINAL |
| COMPOUND LENS OVERALL AXIAL THICKNESS | 0.429 INCHES MINIMUM AND 0.469 INCHES MAXIMUM |
| COMPOUND LENS STYLE | DOUBLET |
| DIAMETER | 1.220 INCHES NOMINAL |
| EQUIVALENT FOCAL LENGTH | 2.603 INCHES |
| FSC APPLICATION DATA | SIGHT PERISCOPE M25,INTEGRATED WITH FIRE CONTROL EQUIPMENT |
| INDIVIDUAL LENS STYLE | DOUBLE CONVEX AND MENISCUS DIVERGING |
| MATERIAL DOCUMENT AND CLASSIFICATION | MIL-G-174, CLASS 1, GRADE C MIL SPEC SINGLE MATERIAL RESPONSE |
| MATERIAL | GLASS OPTICAL |
| REFRACTION INDEX | 1.5170 NOMINAL AND 1.6490 NOMINAL |