My 2-year old chew monster Dozer (Corgi/Hound Mix) can kill a tennis ball in 10 minutes, and get through a 16" beef tendon in 40. I am truly impressed with this toy. He has had it for 3 months now, and did not put it down for the first 2 weeks! At present, it has one tiny tooth impression on it. One. He loves gnawing on it as-is, and goes nuts when we fill it with peanut butter and treats. It even survived a 24-hour tug-of-war play date with his new pit bull friend Sushi.
Very pleased with the product, and considering other items from the line for the future!