| ELEMENT LEFT SURFACE RADIUS | -1.283 INCHES AND 3.449 INCHES |
| ELEMENT RIGHT SURFACE RADIUS | -1.283 INCHES AND -5.724 INCHES |
| ABBE CONSTANT | 57.400 AND 36.600 |
| AXIAL THICKNESS | 0.118 INCHES NOMINAL AND 0.059 INCHES NOMINAL |
| BACK FOCAL LENGTH | 4.165 INCHES |
| COMPOUND LENS EDGE THICKNESS | 0.156 INCHES NOMINAL |
| COMPOUND LENS OVERALL AXIAL THICKNESS | 0.177 INCHES NOMINAL |
| COMPOUND LENS STYLE | DOUBLET |
| DIAMETER | 0.590 INCHES NOMINAL |
| EQUIVALENT FOCAL LENGTH | 4.204 INCHES |
| FRONT FOCAL LENGTH | 4.133 INCHES |
| FSC APPLICATION DATA | FIRE CONTROL,RANGE FINDER,MK 57 |
| INDIVIDUAL LENS STYLE | DOUBLE CONVEX AND MENISCUS DIVERGING |
| MATERIAL DOCUMENT AND CLASSIFICATION | JAN-G-174, GRADE C MIL SPEC SINGLE MATERIAL RESPONSE |
| MATERIAL | GLASS OPTICAL |
| REFRACTION INDEX | 1.5720 NOMINAL AND 1.6170 NOMINAL |