Depends on how ya rig it up ...
I have mine wired to the left rear tail light so that it burns as a maker light only ... some wire it to the tag light ... you can wire it for a brake light if ya want as well or to burn as both ... you can wire it to flash as a back up warning ... you can wire a switch to turn it on and off as you like
It all comes down to what you want it to do ... check out the DIY section
Good stuff there
