I have a 10.5 month old, 90 lb Doberman puppy - he loves his toys but is big and rowdy and regularly punctures squeakers in the course of normal play. I appreciated being able to buy these replacement squeakers in bulk; now I have them on-hand to use as needed when fixing my puppy's toys. Since I have such a big bag of them now, I've even added squeakers to toys that didn't originally have any inside. I'm happy with the size of the individual squeakers as well - they're a good "general purpose" size.I'm giving the Durability and Sturdiness 5 stars because they are pretty on-par with other squeakers and I don't have an expectation that they'll last forever or be puncture-proof etc. The squeakers I received were all intact and in good working condition.