For electronic transformers (MET and other makes) and light bulbs (ohmic load). (Phase cut). Hum-free, short-circuit proof, with overload protection, lamp-friendly soft start. With memory function, can be switched off. To be completed with: Sensor surface System M 5776.., 5701.., 5704.., System Surface 5737.., AQUADESIGN 5738.. TELE sensor surface System Surface 5709.. Extension operation: With mechanical buttons. Extension operation: Relay universal insert 575897. Version: 20-315 W.