Universal dimmer switch, Power MOSFET up to 400W. Automatic lamp detection. Bidirectional. Standby loss only 0.3 watts. Minimum brightness and dimming speed adjustable. With children's room, snooze and light alarm switch. Also with light scene control and constant light control. Series-mounted device for mounting on a mounting rail. Universal dimmer switch for lamps up to 400W, depending on the ventilation conditions, dimmable energy-saving lamps ESL and dimmable 230V LED lamps also depending on the lamp electronics and the dimming type. Zero-crossing switching with soft on and soft off to protect the lamp. Switching voltage 230V. No minimum load required. The set brightness level is saved when switched off (memory). In the event of a power failure, the switch position and brightness level are saved and switched on when the supply voltage returns if necessary. Automatic electronic overload protection and overtemperature shutdown. Connection to the Eltako RS485 bus. Cross-wiring bus and power supply with jumper. The upper rotary switch LA/LRN is initially required for teaching and determines during operation whether automatic lamp detection or special comfort positions should be used. The LED accompanies the teaching process in accordance with the operating instructions and indicates control commands during operation by flashing briefly.