Achromatical, 5:1, RMS, incident

Achromatical incident light objectives for tube length 160 (RMS thread, parfocalizing length = 45 mm) 

Magnification: 5:1
Focal length: 25.39
Numerical aperture: 0.10
Working distance (mm): 18.5
Theoretical sharpness depth (mm): 0.028
Parfocalizing length: 45