Coolqiya Wireless Doorbell with 2 Remote Button and 3 Plugin Receiver, No Batteries Required for Receiver over 50 Chimes, White

Specifications: Size for Receiver: 3.1*3.1*1 inch;Transmitter:3.4*1.25*0.67 inch Working distance range: 900ft~1000ft (in an open air, no obstacles) Ring tone: 52 pieces selectable options Volume: 4-level adjustable volume (30 to 110 db) Receiver Power: AC 110V (US) Transmitter Power: 1 x 12V Alkaline Type A23 battery (included) Power consumption of receiver: Power consumption of transmitter: Working temperature: -30?~70? Rating of waterproof: IP55 There is blue LED Flashing on transmitter and receiver to alert When you press the transmitter, and the receiver receiving the signal. Usage: Commercial/Residential/Assisted Living (It can be used as paging devices for elderly care and nursing residents.) How to set different ring tone for each transmitter Firstly, please plug receiver in to a regular wall socket, and please long press "volume control button" on receiver for 5-7 seconds untill you hear "ding" with blue light, that means entering the pairing mode and the following steps will help you make them paired:1. Firstly please seclect the music you want by pressing "music control button" on receiver.2. Then long press "volume button" on receiver about 5-7 second till you can hear receiver "ding" and there will be flash blue light. At this moment, please immediately press transmitter button (for 2 or 3 times if need) to pair with receiver.3. Finally you will hear the music you set, which means your operating is completed successfully. 4. The operation method is the same for adding other receiver or transmitter. Note: The battery for transmitter has been installed. Please pull out the insulating strip before using. Package Includes 2*Transmitter 3*Receiver 4*Screws & Anchors1*Screwdriver 2*Double-Sided Adhesive Tape 2*12V A23 Alkaline battery for transmitter 1*User Manual