Vivitar Nikon F (pre-AI) 28mm F/2.5 f2.5 Wide Angle Prime by KIRON. Tested.  991

A classic, all metal and glass fast wide angle lens by Kino Precision (Kiron) in the Nikon F mount.  Well used but in good working order.

Notes:  

1) De-clicked aperture, and f/ numbers on the aperture ring no longer line up with the index mark on the lens barrel.  So knowing what aperture you have dialed in is guesswork.  The "A" setting on your mirrorless camera will be your friend.

2) Slightly dented filter ring.  Filters go on & off OK.

3) Moderate internal dust.  (The photos show some external dust that I failed to blow off.)

Smooth focus, snappy aperture.  Heavy duty construction.  

The sample pics were taken on a Nikon Z full frame.  Easy to adapt to any mirrorless with a cheap adapter.  And of course work great with any Nikon film camera from the F2 and earlier.  Works on other Nikon's that can mount pre-AI lenses in stop down metering mode (like FM and FE.)

Thanks for looking.