Came with new built house. This does work. However, it is the loudest disposal I have heard in 50 years. No excuse for it. I just left one in another house which worked better but was so quiet you could barely tell it was on.
Just purchased this disposal and got it installed. Approx 25 min to install and was very easy. 1-10 on being easy 1 being the easiest I would give it a 4. This disposal is very quiet, may be the quietest that I've ever owned.