I bought this Styrofoam head first for my 90 centimeters long wig, which is absolutely a bad buy .. The head was dropped due to the polystyrene around permanently, because he simply could not keep as much hair. Since I have the wig but anyway tailored to my own head to about a length of 30 centimeters, which was no longer a problem, they kept upside down then. My 50cm wig can I just sit down on the so Wigs mind that they will not tip over.
So for wig to 50 cm of the wig head is great, for a long wigs I would not recommend it.