100% Made in USA
The outerwear is a micro mesh of plastic that surrounds the entire filter
like a sock.
Water beads on the surface due to some hydrophobic (water repelling) oil they
treat the outwear with. Supposedly this treatment only lasts like a year, but
I've had mine on longer than a year and I believe it still helps so I'm keeping
Your air filter is like a cotton gauze or paper element. If you splash water on
it, IMMEDIATELY the fibrous material is going to soak up the water.
However, if you cover the air filter with a water repelling sock. (Think
trampoline like material) The water bounces, rolls, beads, and falls off the
sock, thus not soaking into the fibrous materials of the filter element.
I believe the outerwear protects the filter from large debris, big to medium
size dirt particles, mud, and water droplets.
The air permeability of the outwear is excellent and although it seems like it
only would be restrictive, I doubt that it would be measurable in a dyno test.
Of course the outerwear will not protect from hydrolocking. I did the
experiment of submersing the sock completely in water. The water will almost
immediately fill up the sock through the walls, and then slowly drain out of the
sock once the sock comes out of the pool of water. I don't think ANYTHING short
of a snorkel is going to protect your CAI from hydrolocking so just don't drive
in deep water.
On the other hand. Put your hand in the outerwear sock and drip and splash
water on the sock, and you'll see that it does offer some degree of water
Perhaps it's main function is to act as a pre-filter to your air filter to keep
it a little more clean at the expense of decreasing air flow by a marginal
Then there's the big question... What size do I get and where to buy? This I
don't know... (Retail price is like $20)
Should everyone get it? Probably not b/c they don't need it.
Why did I get it? For peace of mind that there's a protective sock on your air
filter. Maybe it'll bounce bugs, debris, and splashes of dirt off the