| Model | AT-B4 | AT-B3 | AT-B2 |
| Telescope | Objective aperture | 32mm(1.26 in) | 36mm(1.42 in) | 42mm(1.65 in) |
| Magnification | 24 × | 28 × | 32 × |
| Image | Erect |
| Field of view | 1°25' | 1°20' |
| Resolving power | 4 .0" | 3 .5" | 3.0" |
| Shortest focus | 0.3m (1.0 ft)(from center of instrument) |
| Stadia multiplication constant | 100 |
| Stadia additive constant | 0 |
| Coarse sighting | without | with | with |
| Compensator | Damping system | magnetic |
| Working range | ±15' |
| Setting accurancy | 0.5 " | 0.3" |
| Leveling accurancy | 2.0mm | 1.5mm | 1.0mm |
| Horizontal circle | Diameter | 103mm(4.1in) |
| Graduation/estimation | 1°(1 gon)/ 0.1°((0.1 gon) |
| Sensitivity of circular level | 10'/2mm |
| Horizontal fine motion screw | Double-sided endless drive |
| General | Water resistance | IP66 |
| Base | Concave and flat |
| Base screw | ¢5/8in |
| Size(W*D*H) | 215*130*135mm | 215*130*140mm |
| Weight | 1.70kg | 1.85kg |
| Case | 1.38kg |
