Indoor motion detector with crawl protection. The sensor module detects moving heat sources (e.g., people) within an adjustable detection range and activates a stair lighting duration. The sensor module features a light sensor with an adjustable brightness threshold, ensuring that the lighting is only turned on below a certain brightness level. Optional presence function: brightness-dependent stair lighting function, duration on/off. Includes: relay switching module, universal dimmer module. Brightness-independent stair lighting function with: central control module. Detection range: 180°. Control element: function switch (permanent off, auto, permanent on). Number of levels: 6, number of zones: 46. Recommended mounting height: 1.1 m, range: 8 m to the right/left, 12 m forward. Sensitivity: continuously adjustable, light sensor: continuously adjustable from approximately 10 to 1000 Lux. Delay time: continuously adjustable from approximately 10 seconds to 30 minutes. To be completed with: relay switching module, universal dimmer module, central control module. An additional adapter frame is required when used in the designs ELSO Fashion/Riva/Scala.