Normally I avoid Chinese sourced (low quality and bad odor and short lived) rubber products of any kind. (yes they do use bad grammar on their packaging!) It is hard to wade into this category of product blind and try to tease some helpful info from these reviews. How do you select from the myriad choices offered? No one seems to comment on the quality of rubber these rings are made from. I will say this is my third Beauty Molly Silicon product purchase, and every one is made from odorless and lux feeling rubber. Even after a few dishwasher cleanings, the product feels like it has some sort of lubricant built in. Very smooth and velvety slippery feeling. Yes, this does make a difference in the application! Particularly the established brand Doc Johnson was made from a product that seemed to almost adhere to delicate skin exactly when you didn't want this to happen. So just know that these seemingly could not be made from a better product. It will be interesting if long term the quality endures.
My pet peeve is the lack of emphasis on prominently listing the size of these products. That should be first and foremost as if this is not right, nothing else matters. And then to purchase another of the size you want, you are forced to purchase two other rings that will probably be thrown into the garbage upon receipt.