Please note: our M42 adapter ring could not be suitable for Pentax Takumar Super Takumar Carl Zeiss M42 series（aperture pin does not fully depress, small tabs sticking out), as ours depresses the aperture pin all the way down

1. please judge whether your lens could adjust the aperture there is only Nikon(G),also called AI(G) adapter ring has the aperture control ring, and is only for Nikon G lens,
   If you want to use nikon AI lens on this Nikon(G) adapter ring, it could be attached, but the aperture control ring could not be used as
   there is a pin on Nikon G lens that could move the aperture control ring but no on AI lens.
2. Some buyer mentioned could not adjust the aperture, actually this is because your lens does not have the aperture control function, If your lens does not have a manual aperture control ring, it will stop down to its smallest f/stop by default
3. Since there is no electronic contacted on our adapter ring, so could not transfer the aperture number to camera.