Self-generating Doorbell Clock Hygrometer Room Temperature And Humidity Wireless Doorbell Elderly Pager Visual Doorbell Electronic Device Features: Comfortable set up: the doorbell button to send signals to the doorbell host, which is more suitable for families with elderly and children High gloss transparent mirror material design: mirror material, smoother and transparent, display cleaning, elegant and shape HD digital color display: the atmospheric digital display and PC board display screen based high light greatly enhance the visual enjoyment of the product Door number display function: incarnate a miniature call system, which can distinguish different door number callers Four grade of volume: the doorbell can support four grade of volume adjustment, even if it is far away, it can be heard display, real- control of space temperature: the doorbell is equipped with and Celsius degrees to control the temperature in the space in real, and the screen can display the Product Description: Product name: wireless doorbell Plug: US Plug Specification: 1 transmitter+1 receiver grade: transmitter grade IP44 Working temperature: 0-99 ℃ Working humidity: 0-99% Working frequency: 433.92MHZ ± 75KHZ Receiver voltage: 100-260V/50-60Hz Ring tone: 38 optional Volume: 0-100 dB, 4- Package size:13.5x8.5x6cm/ 5.31x3.35x2.36 inch Gross weight:171g/ 0.38 lb The Package Include: 1 x Doorbell 1 x Dingdong machine 1 x Installation tool 1 x Use manual