It comes with integrated sensors to monitor what happening around over time and it automatically starts and stops.

Parameters

Run Time：

(Flash -25h)---(L1,-5.6H)---(L2.-4.2H)---(L3.-3.0H)---(L4.-2H)

Battery Capacity：

2450-2500mAh

Net Weight：

139g(Including mount bracket

Gross Weight：

110g Inclding Battery

Dimension：

L:105mm W:31mm D:34mm

Brightness：

500lm

Material：

Aluminium Alloy casing

Connector：

type-c

Color：

Grey

Operation Mode：

Manual mode and automatic mode

Water Proof：

IPX6

See more at http://www.enfitnix.com/Navi500-Smart-Bicycle-Front-Light-PG5198108