Microscope lens: spec / data sheet?

I’ve got the Microscope stand with 0.12-1.8x lens . Is there a spec sheet / dimension sheet available, please?

I’m trying to work out if the lens has a filter thread, and if so, what diameter it would be. Since I want to use the microscope for soldering, I really don’t want flux goo on the optics.

I also want to build an LED ring light for it. Sure, I could get out the vernier calipers, but if there are dimensions out there …