I bought the size 10, which are very small, specificly for ice fishing. They do a great job eliminating the "twisting jig syndrom" for me. I have yet to have one break, even on 10 lb lake trout, like I had happen with another brand from "The Mart" fishing section.
I use these swivels for all my fishing from perch to salmon they work great, they are very strong and still small in size. I have not had one break yet.