This all-natural Femur Knuckle is dipped in natural liquid smoke and oven baked. It is Jones' largest knuckle and with no artificial ingredients, this is best for medium to large size dogs. The soft knuckle material is a delicious treat and will leave a hard bone underneath for longer chewing. The Femur Knuckle is the large end of the beef femur bone in the hind leg. All Jones' products are 100% grown and made in the USA.