| BEVEL ANGLE IN DEG | 45.000 NOMINAL |
| BEVEL DEPTH | 0.510 MILLIMETERS MAXIMUM |
| DISPERSION | 64.000 ANGSTROMS MINIMUM AND 65.000 ANGSTROMS MAXIMUM |
| FSC APPLICATION DATA | SIGHT PERISCOPE T42 |
| LENGTH | 62.740 MILLIMETERS MINIMUM AND 63.240 MILLIMETERS MAXIMUM |
| MATERIAL DOCUMENT AND CLASSIFICATION | JAN-G-174, TYPE 517-645, GRADE C MIL SPEC SINGLE MATERIAL RESPONSE LOCATION NOT OTHERWISE SPECIFIED |
| MATERIAL | GLASS OPTICAL LOCATION NOT OTHERWISE SPECIFIED |
| POLISHED PERIPHERY | NOT PROVIDED |
| POLISHED SURFACE | BOTH |
| REFLECTION REDUCING SURFACE | BOTH |
| REFRACTION INDEX | 1.5160 MINIMUM AND 1.5180 MAXIMUM |
| SPECIAL FEATURES | CORNERS ROUNDED 0.237IN. MAX 0.197IN. MIN. RADIUS; RESOLVING POWER TO BE 30 SEC OF ARC OR BETTER AS USED WHENSCANNING CLEAR APERTURE WITH A TELESCOPE OF AT LEAST A 0.5IN. APERTURE; LIGHT DEVIATION NOT TO EXCEED PLUS OR MINUS 2 MIN OF ARC; SPHERICAL POWER NOT TOEXCEED 7 MILLIDIOPTERS; ASTIGMATISM NOT TO EXCEED 3 MILLIDIOPTERS; SURFACE QUALITY 80-50 |
| WIDTH | 24.9 MILLIMETERS MINIMUM AND 25.4 MILLIMETERS MAXIMUM |
| SURFACE FINISH | POLISHED |
| THICKNESS | 4.800 MILLIMETERS MINIMUM AND 5.200 MILLIMETERS MAXIMUM |