The black button has different function settings.
First click: ON, if you leave it like this the device will remain on until it runs out of battery.
Second click: Motion detection. The light will remain on for around 40 seconds to “get to know its environment,” then the light will turn off. Once switched off, the motion detector is activated and the lamp will turn on if movement is detected by the sensor (the small sphere on the front of the lamp).

If you use alkaline AAA batteries, you can expect around 9 hours of continuous battery-powered lighting.
When used for a security cabinet opened 4 times a week, you can expect a lifetime of over 1 year.
Can be used with AAA rechargeable batteries. Note that depending on battery capacity, operating time can vary greatly.

74 mm x 46 mm x 27 mm
90 g