Review (5/5): Better and easier on dolls than a silicone wig cap!
These were exactly what the doctor ordered! I purchased them to use on my ball jointed dolls with a head size of 7/8; 8/9; and 9/10. I've not tried any other sizes so I can't confirm those. You slip it right over the bald head and voila, instant security to hold unglued wigs down.
And by the way, it works on human pony tails too lol