These are the little grub screws used to fill holes on firearms like the top of the Ruger 10/22 receiver. Sold in a 6-pack these little guys are hard to find - especially of you drop them !

Found here on the website and Yes, I know the picture shows 4 but you will in fact receive 6 in the order :

https://dlaskarms.com/product/dlask-...5-grub-screws/