Intelligent And Greeting Sensor Warning Doorbell Door Minder
Put in three pieces of AAA 1.5V batteries, The static current is by microampere 3 pieces of AAA 1.5V batteries can last for more than two months.
Effective alarming detecting distance is 5M~10M
Effective angle 110°
Don't surpass this area when you install it
Alarming sound depth: 75~95 decibels