A mechanical mod is the name given to a device that has no circuitry inside. Usually, a mechanical mod is styled in the shape of a tube, with a 510 thread at the top of the mod and firing button at the base. The mechanical mod will house a battery which will depend on the size of the mod. The batteries could be either 18650, 20700 or 21700 and would need to be charged in an external charger as mechanical mods do not come with charging ports. Mechanical mods are manufactured by companies from around the world and can be made from materials including stainless steel, copper and brass.