I had read that the Oura sizing and standard ring sizing were different. But I was not about spending more money on a sizing kit I would never use again. I was able to get it on the intended finger but the finger soon started swelling. I ended up having to use cold water to get it off and moving it to a less ideal finger. But otherwise, so far I am happy with the purchase. It would be nice if Walmart electronics department would provide a sizer kit for customers to use.