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This 9v battery contained six cells stacked like a layer cake
(lemmy.sdf.org)
Picture of a disassembled Duracell 9v battery. Below the terminal assembly is a clear plastic case where you can see six sets of stacked rectangular terminals and fillings.
I would seriously consider paying for a landline just to have one of those
You can get a cheap SIP line and an ATA and use whatever old-school telephone you want.
It's kind of a different vibe picking up the landline instead of the smartphones, isn't it?
Truly