My dogs loved this product. It was used every day, but it didn't even last 3 months before it stopped working. The "female part" inside the unit that you plug the cord into broke off. I know you can use batteries, but the use my dogs got out of it we would be replacing the batteries weekly. It was very disappointing.Our dog loves it!Helps teach a trick of loading it so the dog can entertain itselfAnd even my wife chases the ball, (good for cardio workout)My dog loves catching the ball. The only thing I had to train him to do was not run forward toward theball because it comes out at a high speed and at first he was bleeding from the impact. I have him sit asafe distance and stay while I count to four, tell him NOW, and the ball shoots out so he can catch it froma safe distance. The ball shoots out at five seconds.My dog loves it!!Too loud as it starts up after sensing the ball is there so my two dogs run away just as I get them talked into getting close to drop it in. If it were quiet I’d buy extras bc that’s the only complaint I have. I’ve got little chihuahuas so the machine is a little bigger than both of them.I have only had this a few days so cannot comment on its durability or if it will last by my little Corgi absolutely loves it and in the morning heads towards it before even eating her breakfast. It was super easy to set up and has three settings for the distance. It does use small tennis balls not large ones just in case you have a big dog I would not recommend.I ordered a new unit for close to $150. I received a very obviously returned unit with the box taped together and scratches all over the unit. The best part was there was someone else’s dog’s hair on the unit! It was supposed to come with three tennis balls, but it didn’t! What a shame, my dog probably would have used it.