This was an "existing" 1 gang to 3 gang wall mounted unit. This took a little longer as the hole cut had to be absolutely accurate in size and close to the mounting stud. This box is very sturdy and well built which makes it very easy to mount on top of the typical flimsy wall box that you already have. The box costs more than twice as much as a regular box, but I don't have to worry about using an outlet breaking the box. I would recommend this product to anyone who takes pride in their work and doesn't mind spending a few bucks more for quality products π. The ONLY reason I didn't give this product a 5 star rating is because of the price.