Was able to find them by searching "snaps" and "fishing". Each brand calls them something a little different.
I use the really small ones for panfish and the larger ones for my bigger crankbaits and larger bettle spins.

If you have rigs that are certain lengths it works out well cause changing up your bait doesn't shorten your rig due to retying.

Like anything they have their pluses and minuses. (sp)