Bluetooth version Staircase Light 2-in-1 Controller,Can be set with buttons and controlled by Bluetooth on the phone Button settings. stable and ,Adjustable speed/steps/running length As soon as the person arrives, the light turn on,Lights on when people come, off when people leave Colour:Black Material:plastic Due to different product batches, the appearance may be different, which does not affect use. Package Contents: 1x Stair Tread Light Controller Kit Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.