When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
had air horns on a motorcycle and they would fill with water and trash if open directly to air flow. Had to buy a couple of deflectors for them to keep water and trash out.. I would guess this is to divert water and trash away from the inlet.