A complete doorbell with receiver powered by 3 x AA 1.5 V batteries (not included), and button (transmitter) that works on kinetic energy. This means the button converts the force exerted on the button into energy, which sends a radio signal to the receiver. One button can be interconnected with up to 100 receivers. Up to 4 buttons can be connected to one receiver. The system can be easily expanded if e.g. the house is big or has several entrances. The button is waterproof (IP44). Choose between 32 different rings and combinations with ringing and flashing LED.