2 * 2700 mAh ER14505 Li-SOCl2 Replaceable Batteries Battery Life: Around 3 Years ((10-min Interval, 2000 People per Day) Bi-directional People Counting without Sunlight Interference Based on IR Breakbeam Technology Visual Data about People Counting Via Screen Smart Scheduled Hibernate Mode to Save Battery Power Advanced Features: Milesight D2D Controller NFC Enabled IP30 Rated Technology: IR Breakbeam Installation Height: 0.7m ~ 1.2m Detection Range: 1.2m ~ 3 m Detection Rate: Up to 80% (Single Person: Up to 99%)