I have always struggled with picks, don't like them, I like using my fingers but I also like the sound of the picks for solos and certain rhythms but always struggle to change between finger and pick, always drop it and this thing, oh yes, amazing, my way of playing has changing enormously. I can use it as a standard pick and also use al my fingers in the next second and go back with a perfect flow.
Simply amazing thing, I don't understand how no one else has come with something like this.
And you would say, but there is tons of thumbpicks out there, I have try them, no, they are not the same, they don't work for what I wanted, too long, or you would need to modify them. Never managed to make them work for me. This is a different thing and it is amazing for any musical style, really any.
Only con, but this is normal in all thumbpicks, is that the the ring adapt exactly to the size of your finger, I have big hands, but that is fixed with a lighter warming them and adjusting the tightness. I did that in couple of minutes and they now fit perfectly.
This is my thing now and the way I play.