CACAZI FA86 Self-Powered Smart Wireless Doorbell Set with Transmitter + 2 Receiver Doorbell Support 150m Distance - White/US Plug Self-generating transmitter: No battery is needed. A finger press can trigger the generator to convert into electrical energy Not just a doorbell but also a pager: The elderly,children,and pregnant women have needs,just click to know,sleep at night with peace of mind Easily deal with various places: In villas/apartments/office buildings/hotels/nursing homes and other places 5 levels of adjustable volume whatever you want: The doorbell has five levels of volume,which can be adjusted freely. (Volume can be adjusted,light reminder) Anti-interference,no crosstalk: Digital circuit design,multiple sets of use will not cause cross talk,effectively avoiding the troubles caused by mutual interference between neighbors Specifications: Model: FA86 Music: 60 music tracks Volume: 5 levels of volume (adjustable to flashing light only) Transmitter: No batteries required,press to power Receiver: light on only when the bell rings Transmitter size: 74 x 40 x 20.3mm Receiver voltage: plug in and use (AC110V/220V) Receiver size: 92 x 62 x 32mm Remote control distance:150M in a straight line on open ground Package included: 2 x Receiver 1 x Transmitter 1 x English Instruction Manual 1 x Installation Kit Other items not included