Rubber-backed Carpet?

I have a bathroom with vinyl tile floor, which currently has some carpet with a soft rubber backing. It's like a giant bath rug that covers the whole floor; the rubber backing keeps it from sliding around. Where can I get new carpeting like this? I've checked the usual suspects--BB&B--but the bath rugs they have aren't large enough to cover the whole floor. Does this stuff have a proper name that would assist me in a search, other than "rubber-backed carpet?"