Sources for keychain style spare battery carriers

I know CountyComm has the delrin “battery lockers”, but their shipping isn’t cheap
( and when I asked last, many warned me of Delrin toxicity if a battery vented…)

Has anyone managed to find proper sized containers for
16340/AA/AAA and even 18650 batteries?
Lots of aluminum pill fob styes on Ebay—but its difficult to check interior dimensions
against actual fit.

This holds the 18650, but would have to be modified for a key chain.

Thank You.
Keychain not mandatory.
That looks perfect for a 18650 in a Bug Out Bag

How tight does an 18650 fit in that match case? Do you have inside dimensions?
Thanks in advance

My protected 3400 Panasonics fit fine in it, the width and height are easy fits, it seems like it is made for it.

Mine is a number of years old, so I don’t know if the manufacturer changed the dimensions or not, but they are cheap enough to check out, they can also fit into a lot of knife holsters to carry on the belt.

Found some of those 2piece plastic rectangular storage containers for end mills
at the Swap Meet today—they looked plenty protective and
water resistant—but the seller would not sell them separately from the mill cutters.

Any machinists here have these?

Found a perfectly sized silver “pill container” for holding a spare 18350/16340 battery @ DollarTree stores
Not super sturdy—may be pot metal or plastic— but perfectly sized to hold a 18350
rattle free with no extra space.
Has o ring and key ring attachment, gonna add to my Bug Out Bag