Dimensions: outer diameter 5.5inch, inner diameter 4" (check the picture 5), dill a hole about 3.85" to install it; Function as back up light, reverse light and running light.
HARDWIRED with THREE WIRES: Black Wire is the Ground; Red Wire is the high brightness for backup or reverse light; White Wire is the low brightness for running light, one function at a time;
Offering customer technical service, feel free for technical, installation and use question.