It completely varies by each individual dog. Our cofounder’s golden retriever is 85lbs and will chew up most toys, but has never wanted to chew up the classic rings, and so she does not need the extra tough version. We’ve tested multiple large dog breeds with similar results.

Know that the HurriK9 rings are not "chew toys". They are not made to be left out for your dog to idly sit and spend time gnawing and chewing on the rings. But for those dogs that have a stronger bite, these spandex rings will be very difficult to chew through and will last a long time!

So it comes down to judging your dog’s bite strength and overall ability to chew up toys quickly. You can always try the Classic Rings, and if they don’t last as long as you would like, you can always buy the Extra Tough Rings separately at a later time.