It is an Optivisor and is available at jewelry and dental supply houses. It is available in various magnifications. 2, 3,4,5,7,10.
2 = 1.5 focal distance 20"
3 = 1.75 focal distance 14"
4 = 2 focal distance 10"
5 = 2.5 focal distance 8"
7 = 2.75 focal distance 6"
10 = 3.5" focal Distance 4"
The stronger the magnification the closer the focal distance.
Apache
Last edited by Apache; 07-22-2020 at 02:00 PM.
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