It's not fake. It's genuine low capacity battery. Duracell and energizer do the same trick.
Really?? Even after I posted the pic? Can't you see that they are intended to be a secret hiding place?
https://usa.banggood.com/Hot-Battery-Shaped-Secret-Stash-Safe-Money-Pill-Hidden-Container-Screw-Box-Case-p-1571058.html?rmmds=search&ID=3145&cur_warehouse=CN
They only had the one size when I ordered them but I see from the advert now that even the smaller size are marked as size "D" Now, I have to go buy the D size since they are correctly marked.
Although, I do like the spin....better as...Special zero capacity batteries with screw tops.
Edited: Added link to where purchased.
That is actually not a bad way to hide your diamond rings or something like that. Trouble is, if that product sells well, thieves/burglars would know about it. If they do break in, along with your rings and other unmounted diamonds your entire battery stock may be gone as well.