Yes, it is indeed Nikon f mount. 

Dear Customer, so sorry to tell you that this adapter won't allow your nikon 1 s1 lenses to mount to my canon t2i. 

The adapter is designed for Nikon lenses, including D mount. If the Tamron fits the Nikon D80 it should work. As for the lack of aperture ring on the Tamron ... not sure about that. Perhaps the Nikon D80 has an in camera aperture selection. 

There are two types of FD mounts
FD/FL Breech-Mount (with a silver ring, you need to rotate the silver ring when attachment and removal), breech-lock mounts are identified by the silver ring
New-FD Bayonet Mount, bayonet mounts are identified by a red dot next to the lens release button

Here are the steps to install breech-mount version

1. Set your lens to smallest except for auto(bayonet mount only)
2. Rotating the Lock-Open ring of the adapter on the OPEN side
3. Line up the red dot with your lens and adapter ring(if yours is bayonet mount, just turn the adapter ring towards clockwise direction to make lens and adapter tight,then ignore the 4th step)
4. Turn your lens ring towards counterclockwise direction to make the adapter ring tight with your lens
5. Rotating the Lock-Open ring of the adapter on the LOCK side to engage the aperture closing pin

Operating the adapter

1. If you'd like to operate the lens aperture with the adapter; on your lens, set the aperture to the smallest opening and use the adapter ring
2. If you'd like to operate the lens aperture with the lens; place the adapter ring on the small aperture(Lock place) and control the aperture on the lens

 

Firstly, let's talk whether you need Nikon AI adapter ring or Nikon G adapter ring.
If your lens mount is AI, please choose AI one, if it is G please choose G one, there difference between them is G adapter ring with a aperture control ring.
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.
So why have a separate adapter for the lenses with the 'G' designation? While the G lenses are the still the same physical F mount, the G indicator means there is no aperture dial on the lens itself. So while the G lenses will physically fit the standard F mount cameras and adapters, there is no way at all to change the f-stop on the lens. The adapters marked as Nikon G Mount are specifically made for those lenses in mind and have a dial built into them that allows you to control the lens iris from the adapter!
so here let's discuss the 4 items
KF06.068 AI mount, aluminum material
KF06.286 AI mount, with 1/4 Female thread screw for mounting onto the tripod
KF06.309 Ai mount, cooper material
KF06.070 G mount, aluminum material