StarDot Technologies netcam XL User Manual page 43

it from StarDot, it will be noted on the packaging.
The only difference between a C-Mount lens and CS-Mount lens is
the C-Mount lens requires a 5mm spacer between the lens and the
chrome back-focus ring (the spacer is included with the standard
8mm C-Mount lens that ships with NetCam).
If your lens is CS-Mount, you do not need to use the included 5mm
spacer. If your lens is C-Mount, unscrew the black 5mm spacer
from the back of the 8mm lens and screw it onto the back of the
C-Mount lens you will be installing on NetCam.
3. Screw the new lens (with attached spacer if the lens is C-Mount)
NetCam XL Page 43