I can only speak for my Nikon 50mm f1.8 Ai-s manual focus lens and the Olympus Pen-E PL7. The K&F Concept® Nikon - M4/3 lens mount adapter ring for Nikon AI lens is well suited for this. The adapter sits firmly and without play on the lens and can be easily attached to the m4/3 bayonet. 

No, the adapter is for CANON EOS EF to CANON EOS-M lenses. The bayonet for EF-M and MFT is different. In addition, the EOS M cameras have a back focus of 18mm and MFT a back focus of 19.25mm. However, there is a Viltrox adapter from EOS-M to MFT with the correct lens distance 

This adapter fits the Panasonic G85 perfectly. If your lens is a Nikon G lens, then you should have no problems. The version of this adapter I have is M43 (Micro 4/3rd) to M42 lens. Hope this helps. 

hello panasonic lumix g7 is m3/4 mount, so the adapter ring could not work for panasonic lumix g7 

The adapter will mount the lens and you will be able to use it manually. However, my copy of the adapter does not allow the lens to be fully mounted all the way until it clicks into place. It doesn't quite make it, but it's still very solidly mounted. Also, the manual aperture linkage doesn't work properly (on my copy, at least) so exposure is controlled only by shutter speed and/or ISO. You will be able to manually focus and zoom the lens but no VR, of course. It will be a frustrating experience. Instead, get a 14-140 Panasonic zoom if you can afford it!