Our dogs (2 half-lab/half-weimareiner) love these. Especially when they were younger they would tear through most toys in no time. These last almost forever, and are the perfect size for our dogs to play fetch and strong enough for them to just gnaw on. The hollowed area keeps them from being too heavy to play catch. We had 2 of them for years, but eventually lost both of them (probably hiding in the sofa cushions or behind a piece of furniture somewhere). Going to order two more. Get these and you won't be disappointed.
My dog isn't much of a ball-fetcher, but I like this ball for its durability and easy-to-see colors. The "treat spot" is a little too big to securely hold anything except for peanut butter, but you can freeze chicken broth or water inside and it makes a fun treat for your dog on a hot day.