Hooks.

[knotnot]

I have an older box of Talon hooks sz. 1.5 and are black.
Why is the eye of these hooks folded around and have a gap between the main shaft and the extra bit off the eye?

[phearless]

It is called a loop eye.
Very strong.
The gap will close when you tie the thread on.

Most good salmon/steelhead irons are loop eye.
TMC, Partridge,Daiichi etc.
Preferably tapered wire. Skinnier toward the end of the loop to keep bulk down for the classic look.

You have probably seen TULE on a box of hooks sometime = Turned Up Loop Eye.
TDLE = you guessed it, Turned Down Loop Eye. i.e. Partridge Bomber Hooks.

[knotnot]

Thanks for turning on the light in cranial cavity !