Well I have lived more than 40 years, but apparently I still don't know what that is. My first thought was it was a floating key ring for a boat. But if you have to be over 40 to recognize that, does that mean they no longer make floating key rings for boats? You drop your keys overboard and they go glub glub glub?
It’s a “peep show”.
There’s a view port and a picture inside.
Content varied from cartoons, jokes, scenery or naughty pictures.