83
Found on a beach south of England
(sh.itjust.works)
Let us help you identify that mysterious object you’ve found.
Currently in CHALLENGE mode: If you've got something obscure knocking about, post a picture, and let's see how we do. Please prefix such posts with "CHALLENGE:" so we know we've got a fighting chance.
Looks like a 6V alkaline battery, without the top. Here’s someone opening one:
https://youtube.com/watch?v=zoTeMEXZfXs