Yes, the ocular lens/eyepiece unscrews.
2 3/4x- Falcon
4x- Hawk
6x- Condor
10x- Vulture
I have a 4x Hawk I was going to mount on my 1953-vintage M70 '06, but I went with a Leupold 3-9x instead. Sometimes one simply has to bow to practicality. The Unertl will get a ride on something sooner or later. Perhaps I should drill and tap my 99T for it.