I just added a ZAP to my Provari but more importantly a Tatroe Base. With this base I can opt to run just the base for a 18350 batt or the base and extension for a 18490 or just the extension along with the Provari extension and have a 18650.
This is with the Tatroe base and it's included extension running the 18490.

This is with the Tatroe base and it's included extension running the 18490.







Oh, so now its a game? I see how you play now...
I actually didn't see myself having much interest in one of these as I imagined that base would feel rather weird fitting into a front pants pocket. 