I have the 2 sizes. I got them from the warehouse. I have long hair below my shoulders that is fine but lots of it.
I find it works best for me when I don't straighten my hair as the wave helps keep them in place. You put your hair in a ponytail, thread the ring over, wrap the hair around and pin into place. I also like to use a hair tie, once the pony tail is up, thread it over and get the hair tie and place it over and it pulls the hair in tight and leaves all the ends out all messy.
This bun ring comes in a small and a large size as well as two colours for light and dark hair. There's also four bun pins with it to tuck all the messy ends away.
All you need to do is tie your hair up in a pony tail and slide your hair through the ring. Once in place tip your head forward, making sure the ring is completely covered by hair, then put the provided hair tie over the bun to hold it in place. To tidy up the messy ends I like to wrap them around the base of the bun and pin them underneath it.
It's a bit hard to do when your hair is super clean and smooth so it's a good idea to brush through something like a bit of hairspray first to get some grip rather than slipping everywhere.
You get a super polished, professional looking style with minimal time and effort using this. It's become a staple for me when going for a presentable look.