what does this button do?

[fizz]

it's attached to the rear view mirror but not sure what it does. anyone know what i'm talking about? i didn't see it in the manual. and i don't mean the flip either on the bottom of the mirror itself, this button is right under the part of the mirror that is attached to the car itself.

[Rattmann]

A Day / Night light sensor
There are two sensors, one in front and one in back.
When both have light >>>>No Dimming
When rear has no light and have light shining on front only>>>>Dimming

[fizz]

cool thanks for the info.

[Gosha]

No its a VTAHK activator

[Deaner]

actually, it's for the nitrous boost enabler

[fizz]

not even, i found out it's the date from hell passenger seat ejector