Wireless Doorbell, USB and Battery Operated Door Bells IP55 Waterproof 700 Foot Long Range with 4 Volume Levels 39 Chimes Indicator Light Doorbells Easy Install for Home (1 Receivers+1 Sensors)

Sound Loud Enough Wireless Doorbell for Anywhere – 4 Adjustable volume and 40 to 120 dB, 39 optional Ring Tones. Memory function makes the doorbell remember the last ringtone and volume, no need to reset even if after a power outage.
Long Range Wireless Doorbell IP55 Waterproof – Ultra-long wireless 200M range with waterproof & colorful LED flash light button. Battery Operated Wireless door bells without any cables. The strong and stable wireless signal ensures that you will never miss any visitors even if you are in a big house with several rooms.
Battery Powered & USB Powered Receiver – The doorbell receivers can use battery operated and USB operated. When the battery voltage is lower than 3.4V, the received will prompt ” battery low”; When the battery is low, please plug in the USB powered or replace the battery.