Air intake hose assembly 17750-28010

[Bungrel]

Quick question about the stated part for a 2002 2.0l vvti rav4 engine. It's the hose that goes from the air filter box to an open horn at the front end. 

Anyhow, I'm cleaning up the engine compartment a little, just cosmetic and a bit of de greasing and I see that this component has a woven fibre section at one end. On my Rav it's black with dust. Is this normal or is it a breathing component that might need changing? No problems with the engine's running or operation and fuel consumption seems normal so it's just cosmetic curiosity on my part really. If anyone has a photo of a normal new version that would help as I can't find one on the net. Cheers.