The Stealth has gone through much more abuse & the finish is still pristine on it months latter. I'm pretty sure it's just the standard black extension cap. The finish isn't as durable as the Stealth finish is.
Looks like the standard black ext cap Provape sells...But VF claims different.. This triple-coated flat black extension cap is designed to allow the VF ProVari Stealth 2.5 to accept an 18650 battery. It replaces the standard end cap....
I like yourself use to have Black satin Provaris and no matter how carful I was with them they all developed areas where the bare metal showed through over time.... I now own a Satin Provari....The Stealth one looks great though...so you say your stealth finish shows no signs of wear?