Our EM is now at 115lbs, our yorkie 24. I have given up buying any "small" or "medium" sized toys since the yorkie normally will not touch anything the mastiff plays with. For some reason this Large Bento is a coveted toy. Y will pick it up and hide it in our son's room and come back like nothing has happened. I do not buy the disk refills since M will play with the toy without the disks in it, but I do occasionally put other small treats inside. Y cannot squeeze the Bento hard enough to get treats out, but we do have a small everlasting treat ball (green) for him. M normally steals that. It is small for her and we do also have the large green ball and she loves that too. I have decided that this Bento ball is so popular that I will have to get another, but haven't decided if I should get another large or if I should get one size down for our Yorkie (the hoarder!). Filling: I use Training Treats inside. I lift the nub and squish them in. Sometimes I add a larger piece of something such as a "dehydrated banana piece wrapped in chicken jerky." I don't know if it's b/c the size of these are large that I don't seem to have trouble with filling. It has a pleasant scent. Not sure if that is purposeful or not. Some notes on Everlasting Treat Products (IMO): The discs are costly and once they come out suck to put back in. And if you aren't looking, once they come out--they disappear very quickly into the happy puppy's stomach! The everlasting treat ball (BLUE LARGE) was expensive, but our Mastiff can squish, chew, toss, lick, roll, and happily play without me worrying that she's going to destroy it. It was worth the money, but the next one I get, I will purchase from ZeeBooth. The Bento Ball (orange) is flat on one side and rounded on the other, so it bounces erradically (sp?) when thrown. It has a smaller width than the Large Blue ball (which can hold 2 disks). The green balls are also very chewy/squishy and our Mastiff loves both the small and large, but she seems to prefer the small unless the large has treats. The small is the size of a tennis ball. The large the size of a "large" tennis ball. (Those of you with big dogs will know what I mean). Everyone has a different experience with these toys, but this is mine. I now have 3 toys I can buy our girl that she can't immediately destroy: Her "Boomer Ball," her everlasting treat balls in Large, and multiple Kongs in Red and Black (she has no preference). I encourage any questions below. 8/15/2011: After initially posting a 5star review for this product, I have taken it down 1star. Yesterday while putting treats into the ball, I noticed that some of the nubbies have been scraped or half scraped off of the ball. They are smaller than a grain of rice, however, I will now not be purchasing another of these items and will try a differently shaped item instead. Other than this, the product is still completely solid. 2/21/12: Item still going strong. I haven't noticed many more of the nubbies coming off. 7/1/13: Same as above. I have noticed she doesn't pull this one out to play as often as the green EvT balls. She still does play with it though.
