the dogs love them. they r very hard. my big dog is a heavy chewer. the little ones play with them and try to chew them but i don't think they get very far. the big dog has chewed them all. they get spiney/prickley after being chewed. last for several months. when u have a heavy chewer u need something like these. all nylabone products r the best chew products. rawhide is not and is not vet recommended. cheaper here than stores