"The Gem Wireless Switching System offers you a new way to install lighting circuits in your new build or renovation. Using the wireless switch modules and in-ceiling controllers included in the system means you don’t have to pull cable through the walls. Excellent for retrofit situations where it is difficult to run cable. Use it in new builds to save yourself time, use less cable, and avoid a whole lot of hassle. The dimmable in-ceiling controllers are operated by the switch modules or via the GEM smartphone app." gemwireless.net