These toys are incredible. My doberman who is not yet two years old usually chews new toys up in a day or two. Many of the "unchewable ones" he doesn't like. These toys are great - he loves them and he has not chewed any chunks out of them. They keep him out of trouble on these really cold days, like yesterday when we couldn't go for our usual off leash run out in the fields. He knows exactly where he has left them and I can send him to find one. The log bone shaped toy is the one he lays on the windowsill. Last night he went to sleep with the round ball in his mouth. He has become an expert at catching them in midair.