There are many wireless doorbell kits vailable, though most of them require a 12 volt A23 battery in the transmitter and, when the battery fails, so does the doorbell. This device uses kinetic energy rather than battery power, so this device never requires changing a battery. The receiver chime plugs into any AC outlet and the system has 100 foot inside (300 foot outdoors) range between transmitter and receiver. You can also add additional transmitters and receivers as necessary for your situation.
We have our outdoor lighting controlled in the same manner, using a kenetic transmitter to control our lighting.It has been working fine for two years and are sure this device will do likewise.
It comes complete with all mounting hardware and user manual.