sensor can work day and nightSpecification: Type: Penetrate Wooden Human Sensor Switch Voltage: 12V DC MAX Load: 60W (5A 12V ) Penetrating Wood Thinkness Range:<=25MM Body Detection Distance <=3M Time Delay : 30-35 Seconds Features: 1 Smart Human Motion Sensor sensor switch is used behind wooden board (like kitchen cupboard ,wardrobe, closet..) or glass mirror. It can paintings on dc 12V led light, And it extra bendy to adhere wherever you like,simple and straightforward to instation. DON&;T NEED OPEN HOLE!!! 2 sensor can sense the medium materials: wood plate, rock plate, stone, paper, acrylic, plastic, glass, and diversified non-metallic conductor supplies 3 distance: The diverse thickness sensitive is different, the thinner the better Please don&;t near to steel materials to bypass interference