CCIS Plan achromat. Phasenobjektiv positiv EC-H PL 100x/1.25 (Feder, Öl) (AA=0.15mm)

This refers to the magnification factor of a single microscope lens. A lens with the number 40 is referred to as a scale of 1:40 or simply a factor of 40 times. If you multiply the lens factor by the eyepiece factor, you get the magnification.

Microscope for professional routine applications.