The Home Range wavy puzzler collagen is a single-source protein treat that provides essential nutrients, vitamins, and minerals as well as an excellent source of protein. Created with a unique shape designed to challenge the dog to find a starting point for the chew, while delivering a longer lasting chew experience! Collagen is found below the top layer of skin (two layers below the tough outer layer used for leather, upholstery, and notably rawhide) and is a key element in connective tissue. Collagen is like a glue that holds things together. A 100% digestible treat, collagen wavy puzzler treats are 84% protein. Rated as a medium-hard chew