Description: As an intelligent doorbell different from traditional wireless doorbell, this product, with simple operation, convenient use and stable signal transmission, applies to apartment, villa, unit family, hospital and other occasions. Features: Simple appearance design, elegant and unique. Ultra-low power consumption design, power saving and lasting. Ultra-long distance control, stable signal Indoor ringtones volume is adjustable. 28 chord ringtones for option. Made of ABS material, the product's waterproof grade is IP55, which can resist rain. Specifications: Transmission distance: 300m / 984ft Operating frequency: 4 33.92MHz ± 200KHz Power: 0.1W Volume: 25-110dB Color: Black, White (Optional) Plug type: US, UK, EU, AU (Optional) Package weight: Approx. 234g Indoor receiver Voltage range: AC 110V-220V Operating temperature: -10 - 55℃ Size: Approx. 96 * 62 * 32mm / 3.78 * 2.44 * 1.26inch Outdoor transmitter: Voltage range: DC12V 23A Alkaline batteries * 1 (Built-in) Operating temperature: -20 - 65℃ Size: Approx. 75 * 43 * 17mm / 2.95 * 1.69 * 0.67inch Package List: 1 x Indoor receiver 1 x Outdoor transmitter 1 x User manual 1 x Some screw accessories 1 x Double-sided adhesive tape 1、Simple appearance design, elegant and unique. 2、Ultra-low power consumption design, power saving and lasting. 3、Ultra-long distance control, stable signal 4、Indoor ringtones volume is adjustable. 28 chord ringtones for option. 5、Made of ABS material, the product's waterproof grade is IP55, which can resist rain.