Our supplier says: “The sticks are made of a stretched, baked beef esophagus. There will be some variation in thickness. This chew is much more palatable than the bully stick, so it’s perfect for those picky dogs. Esophagus sticks are firm, yet slightly pliable. It has a tubular, hollow shape and isn’t as dense as a tough bully stick. This is a satisfying chew!” We recommend this popular stick for small to medium dogs!