My 7-year-old lab, a mellow guy but a strong chewer, loves the linking treat toys. He gets some of his breakfast kibble and an assortment of treats and chewable supplements divided among 2 or 3 links, including the elbow and ball, keeping him occupied for a good half-hour. The toys are very resistant to his strong jaw despite showing many teeth marks. The ball's large well restrains kibble from falling out too fast as the ball rolls, and the ball is too big for my dog to chew through it. The elbow is stronger and more durable than the straight link, whose spiral design has weak spots that my dog has bitten through. He can take apart the links fairly readily, but it's not an issue, thanks to the recessed small flaps that slow down the flow of treats. They're shaped like clogs around a large opening at one end, making it easy to pour treats in, and like prongs around the smaller opening, which resists fall-out better. The recess is deep enough so my dog can't chew these vulnerable flaps, a big improvement over many rubber treat toys. Although not soft, the rubber lands on my hardwood floors with no damage and a thud I can live with, unlike a hard plastic cube or bubble. I give this highest marks for a treat toy. The one drawback: it's hard to find treats that fit the openings but don't come out too quickly now that my dog has mastered his flinging technique.