Here is Sig's first run at TC. Looks to be a single 18650 with both sides that are removable which could be cool for aesthetics. I know a lot of Sig fans are ipv haters so this might appeal to them where the ipv4 might not. Not sure what board it houses but probably some yihi version. No doubt it will be found cheaper at other places.
http://www.asmodus.com/Sigelei-75W-Variable-Box-Mod-p/sigelei-75w.htm
http://www.asmodus.com/Sigelei-75W-Variable-Box-Mod-p/sigelei-75w.htm