Wireless flush-mounted actuator for dimmable lighting systems. Can be used in Busch-flexTronics wireless individual control as a stand-alone renovation solution or for wirelessly networked room control with up to 32 devices. Can be integrated into Busch-free home wireless via a system access point with up to 150 devices. Two-wire connection technology (no neutral conductor required). Optionally connectable neutral conductor (recommended for connecting low loads, less than 10 W/VA). With spring-loaded terminals for insertion. With input for extension unit. Can be operated via conventional buttons. Can be combined with the flex extension insert, 64891 U. Remote control via Bluetooth via smartphone or tablet app. Programming via Bluetooth with the Busch-free home Next app or via the system access point's web interface. Optimized for retrofit dimmable LED light sources. For retrofit dimmable LED light sources on conventional or electronic transformers. For incandescent lamps, 230 V tungsten halogen lamps, low-voltage halogen lamps with conventional or electronic transformers, and dimmable halogen energy-saving lamps. Mixed load operation of LED and conventional lamps possible. Operating modes adjustable via app: leading edge/trailing edge phase control. Minimum brightness adjustable via app. Low noise thanks to the use of MOSFET transistors. Short-circuit and overload protection (electronic fuse). Must be installed exclusively in combination with standard recessed luminaire boxes according to DIN 49073 Part 1.