The electronic Yesly Bluetooth Dimmer 15.21 has been designed for controlling the brightness of all common types of lamps. Installed invisibly in a flush-mounted box, the device controls lighting such as LED, incandescent, dimmable energy-saving lamps, halogen lamps, or electronic ballasts via a smartphone or tablet, the Beyon remote switch, or the wall-mounted remote switch. Depending on the type of load, either phase-cut or phase-angle dimming methods are used, adjustable to a linear or exponential dimming curve. Additionally, a memory function is available, which allows the light source to turn on at the last set brightness or at full power during the next activation. Of course, wired switches can also be directly connected to the switch input to continue using existing systems and smartly expand them. Programming and integration into the Yesly system is done using the Finder Toolbox and app, which is available for free on iOS and Android. Communication is based on advanced Bluetooth Low Energy technology and is also 128-bit encrypted. To protect the connected light sources, the device always switches at the zero crossing of the voltage.