This, or similar. (Some I've seen reset, these appear to not do that)
Vape Safe - 2 Cents For Safety Mod Battery Safety Fuse [gv-VapeSafe-2csForSafetyFuse] - $8.99 : MyVape.com, E-cigarette Supplies - Atomizers Cartomizers Mods Juice and more
Yep, good to have a few mechs in the stash! I have a few, mostly "telescoping" so they have no problems with either a fuse or a "kick" module.
Not in stock