1,Sensing Function: It uses PIR motion sensor lighting sensor technology; At night or in dark weather, the receiver will light up when someone comes, and will automatically go out about 30 seconds after the person leaves. 2,Differentiation Function: This product adds the function of distinguishing front and rear doors; Press different buttons and the receiver will sound different music. 3,Strong Waterproof: The door ringl button has a waterproof grade of IP55, and has a built in waterproof adhesive strip; It won't be damaged even if it gets wet in rainy days. 4,Different Modes: The product has four unique mode functions, namely flashing but not ringing, only ringing but not flashing, flashing and ringing, and always lighting and flashing. 5,Applicable Situation: It can be used not only as a door ring, but also as a night light; Users can place it in the bedroom, children's room, living room lamp, kitchen and other places. It is also applicable to office buildings, schools, hotels, etc. 1 x Door Ring1 x Receiver1 x Connecting Line1 x Instruction2 x Screws2 x Expansion Rubber Plug2 x Stickers Item Type: Intelligent door ringMaterial: ABSReceiver Sensing Angle: 120 degreeReceiver Sensing Distance: 0 to 3MVoltage: DC 5VWorking Frequency: 433MHZVolume: 25 to 100DBMusic: 58Waterproof Grade: IP55Working Distance: 200M (open distance)Battery: 1 x CR2032 battery capacity 240MAH (door ring is shipped with built in battery) Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.