Features :

Type:Microscope achromatic Objective lens
Magnification: 4X/10X/20X(S)/40X(S)/60X(S)/100X(S+Oil)
Mounting size :20.2mm
Standard RMS thread
Material:Precision Copper core
Tube length : 160mm
standard thickness of cover glass 0.17mm
for Biological microscope

4X :Numerical Aperture (NA) 0.1; working distance 18mm
10X: Numerical Aperture (NA) 0.25; working distance 7mm
20X (S): Numerical Aperture (NA) 0.4; working distance 0.55mm
40X(S) : Numerical Aperture (NA) 0.65;working distance 0.53mm
60X (S): Numerical Aperture (NA) 0.85; working distance 0.18mm
100X (S+Oil):Numerical Aperture (NA) 1.25 ;working distance 0.13mm