Absolutely recommend Cherry Keeper (cherrykeeper.net). These are made from light-weight 3D printer material that is strong but not heavy. The site allows you to custom order for size and shape of the base ring and several measurements of the cage, so if you measure carefully you should get one that fits snugly without chafing. i recommend the matte rather than the smooth finish, because the matte does not irritate the skin and minimizes sliding which can cause chafing. i do NOT recommend black, as that color dye did once give me a reaction, and if you have the choice and are concerned about irritation, go with plain white.