I will have to ask my friend where she got them but I think PetEdge. They are called Holee Rollers.
The toy box comes to class once every 8-12 weeks and the dogs each get their turn to go to the toy box and pick a toy. It is really fun to watch since some of them really get into digging around for a "favorite". It has all sorts of toys to choose from: stuffies, squeakies, tugs, toss toys, and balls.
Of all my dogs L'Ox is the only one who really loves toys. He loves balls, stuffies, tugs and will even work for toys not just for food. So he really loved the trip to the toy box yesterday.