LightwaveRF SATIN STEEL 1 Master / 1 Slave Hard Wired On/Off Dimmer. These 1 Master / 1 Slave dimmer switches can be installed into existing twin wall socket box that has a one way and a two way switch. The Master can be controled by installing a slave switch at the other end of the existing 2 way circuit and can then be controlled by Smartphone, tablet or PC. The Slave switch can control a master at the other end of a seperate 2way circuit. Slave switches operate with the master and cannot be controlled by remotes, PC or smartphones.