Standard Set:
1 receiver +1 doorbell button
Wireless Range :
400M/1300ft
Power Supply:
Receiver:City Power Doorbell button : Maxcell CR2032 (Included)
lifespan of the battery:
6-10 years based on 30 times per day
Volume:
85-97dB and 5 levels adjustable
Combo with:
PIR motion sensor /Magnetic sensor