LOMO Objective, Achromat, 20x, 0.40 N.A., RMS:LOMO OB-EAB20 objective is specifically for our LOMO Multiscope microscope, any configuration, although it will work on any microscope with an RMS threaded nosepiece. It has a 33mm parfocal distance which is short by today's standards, so it will not be parfocal with DIN standard objectives (it will still work fine regardless of the other objectives on the microscope - the microscope will just need to be refocused).
This objective is a LOMO 20x achromat. It has a numerical aperture of 0.40. LOMO objective is designed for 160mm tube length optical systems, RMS threaded nosepieces. Lomo Objectives.