fish tank accessory help?

[need help!!!]

i need a ball or something that can fill with water while allowing some air to be in it. i need it to float mid-tank (not sink, but not float at the surface). i have no idea what to call it, so i can't search for it. please help me!

 

[MysteryMan5]

It is called Floater Ball (you can order it off the internet)

 

[evilameba]

why do you need it? what does it do??

 

[Ricky]

Will a fish bowl work? An air pump?