I also had an issue with the conductivity of these buttons. I order about 30 pieces recently because I have had good success with these in the past. About 1/3 of them were fine and worked without any issues and the other 2/3 had conductivity issues. As mentioned by another commenter, the male piece (non magnetic) has a thin clear coating on it that prevents it from making good electrical contact. I tried soaking them in acetone, but that did not work. However, I was able to scrape it off with a razor blade fairly easily. The little circular discs that come with were also a problem, as they look like they were punched from recycled material. There was writing and designs on it and I could only remove them by using a dremel tool. I think it was odd that I received some that were bare metal and worked great and the others had coatings on the pieces and did not work until scraped. I hope this gets cleared up because I love this item!

How many sets come in the package?

These are NOT good electrical conductors. The mating surfaces are coated with a very thin layer of some sort of clear polymer; it's what allows them to spin with little friction. You can sand off the coating, or try to scrape it off, and as it gets worn away, it will provide an intermittent connection. It can be made decently reliable with enough careful sanding.

I don't believe these should be sold under the "E-Textiles" section. I purchased these for a quilt project, but it turns out the pins are designed to be soldered. There are no attachment points for conductive thread, or to be attached to fabric or other textile projects.