There are 4 wires , is Live wire (L); the outermost line is Neutral wire (N);Yellow line and inside line connect to light bulb or -saving lamp . Function :Auto switch on/off in the dark when you enter into the induction range, and the time delay has 3 way of 15 seconds, 45 seconds, 5 minutes adjustable.In addition to the automatic control of LED lights, it can also be used to control exhaust fans, doorbells or other devices. PIR motion sensor switch has feature of small size and , easy to install and operate in room or cabinet, plug and play. Infrared Sensor Switch working voltage :100-240V ;Best sensing distance:3-5M ; Mounting Hole Diameter:25mm/0.98inch Widely Suitable for auto lighting corridors, stairs , bathrooms, basements, warehouses, garages,closet, advertisement light and other places., Weight: 0.0551155655 Pounds, Manufacturer: Tuidzljd