I believe the large ones are the 110qt Sterlites from walmart (they're around $25 each) and the small ones are 30ish quart and are $10 each.
And no, that's not a ping pong ball. That's my Himalayan girl Migoi curled into a ball. She's a 2nd generation hold back for future breeding.
That's really funny, she looks so much like the ping pong balls I've tossed in for mine to play with at the distance the picture is at. Oops.. those will be some pretty babies from her, I'm sure.