I actually made this repair this myself. When the granite hole was drilled the hole got slightly oblong. I made up the difference by wrapping black electrical tape around the Air switch threads. The switch had been installed incorrectly, with the washers--steel and rubber-- underneath the countertop. I put both washers on the top side of the counter. I used silicone clear caulk to seal the switch cover to the countertop. Works great now. Great product.
You would call a plumber for garbage disposal repairs.
It just plugs into the receptacle and the tube goes into the bottom of the button.
The $59.00 does so have a 1 yr. over the counter warranty.
They give you 4 color options to choose from. Stainless, Chrome, Nickel and Other