I just ordered it from a bloke in the uk on eBay. It's high temp silicon, I was going to use it as fuel line hose as well but I read on the net that it doesn't like fuel. I tested it myself and when I soaked it in fuel for a few hours it swelled slightly but went back to normal after it dried. Not sure what diameter the connector on the air filter is but it's the TB duel layer for the mikuni vm26.