The neodymium magnets in these feel surprisingly strong for something this small, which is what sold me on trying them. I've been using the size 3 for about ten minutes each evening and it's become a genuinely easy part of my routine. Only wish the set came with a storage case, but that's minor.
The sizes 4 and 5 fit progressively and smoothly, which made the whole routine feel manageable rather than intimidating. The magnetic rings are strong enough that I can feel them working during wear, and my morning pelvic exercises have become noticeably easier to stick with.
The magnetic pull is subtle but noticeable during use, and that gentle traction makes the whole routine feel more deliberate than my old plain silicone set. Sizes 4 through 6 gave me a clear progression path without jumping too fast.