I like this thumb ring.
I just bought a second, smaller one. Fitting is important, and it’s impossible to find out without trying it on. But these are relatively cheap, so why not? In cold weather the smaller one is better, but when it’s warm I wear the bigger one, lightly taped up. After a number of years of Western finger style shooting I’ve recently branched out into Asian thumb style. At my level at least, this thumb ring is really good.