Because the Niles High Power "stereo" volume controls are easy to install, bell built and robust. I can tell you that they are the only volume control I will suggest to installers to install into their system. Simply put, these volume controls are the best there are. If you are looking to buy yourself a trouble free V.C. be sure to purchase the Niles VCS 100R and rest assured your investment was not wasted. Enjoy.!.