These are the best made Ball Throwers.....I wanted the one for the Standard Tennis Ball, but was not paying attention, and ordered these by mistake.  Since I purchased them for my local dog park, where there are dogs of all sizes, I decided to keep these and ordered new ones.  As for the product, they are the best of the ones they make and since they are being used in a dog park where people are using them non stop, they have to be durable and lasting.  Great product and Kudos to the person who created the product.  I have since ordered four more of the Standard Throwers for the Dog Park...By the way, these were a great bargain..