[ryanianian]

Amazon used skytel pagers for oncall notifications until very recently. I had one in 2014.

[treesknees]

Hospitals and other facilities still use pagers for oncall duties. It's quite common. They're robust and last days without a charge.

[sevensor]

When I carried a pager as an engineer at a factory, it lasted for months on AA batteries. It's been almost a dozen years, so I'm starting to forget whether it was one cell or two. It took me years before I stopped reaching for my hip every time the lights flickered.