two cats, or a cat and a resonator?

Hey all. I was crawling around under my little Tacoma last night (you should too, it's fun!) and I noticed there are 2 bulges in the exhaust before the muffler. Please see the image below. I'm pretty sure the first is the cat. And I'm guessing the second bulge is either another cat or a resonator. Anyone know? It looks like a cat, but wouldn't it have an O2 sensor after to make sure it's working?

Thanks . . .

 

Both CATs. But having just had both of mine chopped and replaced with a single universal CAT I would have to say together they act as a resonator, judging by the new exhaust note.