The original from Fat Daddy directly from the USA.
Here the version 4 Low Profile, a special variation of the version 4 with not changeable and only 1mm thick Top Cap.
Version 22mm Flat (without grooves) Top Cap.
Like the version 4 (Regular) with up to 400° Celsius heat resistant o-rings and insulators and integrated one-piece power connector.
In addition to building your own mods also ideal for repairing and improving purchased battery carriers.