They are for my friend who does bobbin lace, they are called divider pins, you know they sometimes have hundreds of bobbins hanging from those threads on the pillow, when you put one of these pins on the pillow, you can put behind it the pins you want out of the way from messing up your work.
I have not sent them to her yet, I was suspicious of the bigger ones being too thick, wouldn't want it to leave a hole on the pillow... but I will only find out by sending her some.