I say a ring because I've already decided that an invisibility cloak would serve both to hide me and to protect me from dangerous UV rays.
Although I still haven't had my primary question about invisibility cloaks answered satisfactorily. Do they only work for humans? Or if I took it off and threw it in a corner where my cat happened to be sleeping, would the cat (and the cloak) both disappear? Could I wrap Christmas presents in the cloak and thus keep them better hidden than if they were in a bag in my closet or under my bed?
So many questions . . .