Originally Posted by F.I. Inc.

It is the high temp. clear silicone sealant between the carbon fiber and the stainless steel end cap. We use it a precautionary measure for exhaust leaks. If any excess is peeling than just cut that off with a razor blade. Do not pull it out though. Just use the blade.

Enjoy the exhaust and let me know if you need anything else. I look forward to your feedback...

Thanks, Tony