I tried one of these a few years back. the centering hold is not precise enough to ensure an accurate placement of the ring. Secondly the mass was really not high enough on the one I bought to feel it did the job properly. I returned mine, did not feel it really was doing the job correctly.
Wayne's Audio Turntable Periphery Stabilizing Outer Ring
Anyone have any reason to NOT give this a try (besides the price)? Or anyone recommend an alternative? I have great weights/clamps/mats but definitely own a few thousand less-than-absolutely-flat records, and feel like it’s a shame to be missing contact.