*raise hand* Is that one of those tanks to keep things in an innact¡ve state, err... I don't know if I'm expressing myself correctly. I mean to say those tanks, like that that once was in the Depeartment of Mysteries and kept brains in them and that keep the brains from attacking you...

"Or maybe one of those muggle thing- you know, the ones which had a, err, ecosystem in them... it surely don't look like a dark item..."