FAQs from purchasers installing these: Q. What color wire is hot? A. The white wire is hot/positive and the black is ground/negative. Q. What is the best mounting method? A. I have used the flat mount for many on and off road miles with no issues. I adjusted the mount so the single bolt hole is centrally located with respect to the light. Remove the heatsink and reverse the mount to adjust for your installation. The flat mount has a physical stop that will limit the amount of adjustment for the elevation (if vertically mounted) or side to side (if horizontally mounted). A handlebar mount is also included.