SIMPLE TO USE: Drill a 12mm hole in your housings, insert the front-side of the breather vent in, tighten on the lock nut - and you're ready to roll!
BETTER: Than the traditional moisture membranes, because they bolt-on rather than just stick on. Therefore, these headlight moisture vents won't ever fall off - and leave you with a big hole in the back of your housing.
PROS: These are the new standard in the most professional way to keep your headlights dry. For the price, the piece of mind is priceless!