Features:  - High precision electronic materials, combining unique long distance technology, in the same power consumption, make the wireless doorbell remote control distance reach as far as 1000ft in the open air, to be the industry's No.1.  - Using high quality speaker, make the doorbell output pure music, high decibels.  - Adopt the industry's most stable music chip, load 55 chord melodies, and make the doorbell ringtones sweet-sounding.  - Unique product appearance with patent.  - With humanization 5 levels volume adjustment, which meet the needs of different environment and different sound levels.  - With digital double panel circuit design, stable work, robust and reliable in performance.  - CE, FCC, ROHS, PSE, TELEC certifications  - With humanized design, including the double-sided adhesive, mini screw driver, 12V23A alkaline battery, do not need to ask any professional personnel, users can install the doorbell by themselves.  - With longevity design remote control button, press 5 times a day on average, can use 25 years in a row.      Specification:  - Product name:Doorbell  - Item type:AC Wireless Doorbell  - Ringtone:55 Melodies (Optional)  - Wireless Distance :(1000ft)300M in Open Air  - Sound Volume:5 Levels, 25-100dB, Including Silent Mode  - Encoding Type:Learning Code, Easy to DIY  - Transmitter Waterproof Level:IP55  - Working Frequency:433.92MHz±280KHz  - Working Temperature:-30℃~+70℃  - Transmitter Dimension:3.2*2*7.3cm  - Receiver Dimension:8.2*8.2*5.5cm  - Optional Color:Black  - Voltage of Plug-in Receiver:110-260V / 50-60Hz  - Battery in Transmitter:12V 23A Alkaline Battery (Included)      Package List:  1*Transmitter  1 or 2*Receiver(as your order)  1*Double Sided Adhesive Tape  1*Battery  1*User Manual  1*Screw Driver  1*Gift Box