From a reviewer:
I bought the small size and while it is good quality and easy to carry around it doesn't hold much and if I had it to do again I would have gotten the bigger size. The small one cinches to about the size of a cantaloupe so it fits in a backpack but doesn't hold much. The product material is excellent and it closes tightly so you don't drop small toys out the top. I bought it for my daughter who likes to play with legos but doesn't like to pick them up. She can only carry a small number of blocks in this so she doesn't like to use it. I think if I got the bigger size it would have been just what we were looking for, but this little size would be useful for traveling. The product came on time and as advertized so I gave it 5 stars, but word to the wise - size matters.