My dogs get so excited when I pull these out! I put a little Peanut Butter in the grooves at one end and little in the center and it keeps them very occupied. I have had for about 6 months and they hold up pretty well. My dogs are aggressive chewers so they have bitten the edges off but don't seem to swallow the little pieces that do come off. Just thought I should mention that in case you have a dog that may swallow plastic pieces.
My dogs ignored the Kong "out of the box" but quickly grasped the concept when I inserted some treats and filling between the ridges. After a couple of days I had to get another Kong so that each of my dogs had their own chew toy.
Both dogs loved these durable dental sticks.
I got this for my 30 lb. collie/husky puppy to teethe on, but always have to assume that my 70 lb. Labs will also chew on all toys in the house! They all love it. I put some treats inside, seal with a little peanut butter, and freeze. They have all chewed on it at some point. Holds up well to both puppy teeth and strong chewers. They like to chew on this more than the original Kong stuffed with treats. And it's less expensive.
My pet LOVES this Kong. He plays with it and chews on it. The great part is he's cleaning his teeth at the same time!