Here is a fantastic mechanical box mod by Smowell. You can use a one or two 18650's.
The fit and finish is breathtaking. At this price its hard to pass up.
This mod ships from the USA!
THE HARD COPY:
- Recessed 510 threading connection
Floating 510 center pin
Brass battery contacts
Spring-loaded negative contacts
Top spring-loaded firing button, without lock
Powered by 1*18650/2*18650 batteries
WHERE: >> HERE <<
$35.99