This motion sensor alarm ensures that you will not miss any important guests. Features: Style1-SF20R: 5-in-1 multi-mode (Welcome/ Doorbell/ Alarm/ Colorful Light/ Night Light). 4 stages adjustable volume from 25 to 113 dB. Both the sensor and receiver can be powered by batteries or plugged into a USB interface(Batteries and USB cables are not included). For indoor use only. Welcome reminder or anti-theft alarm for shops, homes, offices and more. It offers a detection range of 100 degree horizontally and 15 degree vertically, and a sensing distance of 2 to 8m. It features 5 welcome tones and 36 musical melodies. Specifications: Style1-SF20R: Material: ABS Colour: White Size: PIR Transmitter(LxWxH): 8.2 x 4.5 x 7.4cm Receiver(LxWxH): 7 x 4 x 11.6cm Power Supply: PIR Transmitter: Micro USB or AA alkaline battery x 3 (not included) Receiver: Micro USB or AAA battery x 3 (not included) Working frequency: 433.92MHZ Volume: 80-96db Working Temperature: Reciver: -10℃ to +60℃ PIR Transmitter: 10℃ to 33℃ Working Humidity:＜80% Storage Temperature: -20℃ to 70℃ Motion detecting range: 2-8m Horizontal Detecting Angle: 100 Degrees Vertical Detecting Angle: 15 Degrees Battery lifespan: 5-7 months (based on 30 times per day) Package Contents: 1 x PIR Transmitter 1 x Receiver 1 x Bracket 1 x Double-side Tape 1 x Rubber Plug Screw 1 x User Manual Please note: Due to manual measurement, there might be a tolerance in the product size. Due to the lighting effects and shooting angles, the color of the item and that shown in the