Little plastic thingee on Nikon F

I just picked up what appears to be a pristine Nikon F. I borrowed one over 50 years ago but haven't used one since (pulled away by Minolta). What is the tiny white plastic piece immediately behind the rewind crank? Seems out of place on this hunk of metal.

It is the accessory shoe insulator. There is an adapter that fits over the rewind crank to allow a flash to be mounted, and the metal surrounded by the plastic is the contact for that.

It Will work as an accessory shoe but not as a Hot shoe. The contact is for the BC series flash units that slipped over the RW knob.

abruzzi said:

https://usedphotopro.com/nikon-f-coupler-for-flash-unit-270721?source=category

Click to expand...

This is an early coupler, I think, that allowed mounting a flash unit but does not provide a hot shoe. You can also get a Nikon AS-1 metal coupler that does provide a hot shoe. The AS-1 is correct for the F and F2, there are other models for the F3 and more obscure applications. The reason these exist is because of the removable prism. https://www.mir.com.my/rb/photography/hardwares/coupler/index.htm The AS-1 is fairly common and should be findable at used camera stores, auctions, etc.