Name of the Quartic Surface $z=(x^2-a^2)(y^2-a^2)$

Question

Does the surface defined by the following equation have an specific name? $$ f(x,y)=(x^2-a^2)(y^2-a^2)$$

I've searched a lot and found that $z=x^2y^2$ is called Crossed Trough. However I didn't find any names for the aforementioned function.