This lens could be instead of Semi-apo  Plan Fluor objectives of Olympus microscope 

This objectives series are designed specially used for Ft180  UIS  System

Product introduction and parameter

1.  Apply for microscope of infinite corrected optical system with tube lens FL 180mm, such as Olympus optical system.

 2..  DIN 45mm standard

3.  20x, 40x and 100x objectives have spring-loaded(retractable) front ends.

4.  All design of objectives’ shell allowed to be OEM as your preference.

Magnification	NA	WD(mm)	f´(mm)	R（μm）	DF(μm)	on object （mm）	on image (mm)	DIN screw
4X	0.13	17.15	45	2.58	43.74	6.25	25	4/5”
10X	0.30	7.68	18	1.12	7.82	2.5	25	4/5”
20X	0.50	1.96	9	0.67	2.53	1.25	25	4/5”
40X	0.75	0.78	4.5	0.45	0.97	0.625	25	4/5”
100X	1.30	0.15	1.8	0.26	0.27	0.25	22.5	4/5”