"Collars" for Vivi Novas?

[Roxstar]

Where can I get a collar (I think that's what they are called) for my Vivi Nova. My setup looks weird with nothing around the bigger thread on my eGo. I've seen other setups that look normal, and I could be totally wrong on this "collar" thing, I really don't know for sure what it's called. What do I get and from where? Thanks.

 

[redg8r]

eGo Thread Cover (DCT/Nova Base) - MyFreedomSmokes.com
The "large" fits well under a reg nova.

 

[Roxstar]

Thanks redg8r!