>>106188445
it's some chink mouse i got my dad a few years back, it's flat and takes one AAA battery. If you google "mouse black wireless" it's one of the first pics you get, except that one takes a battery. Also, i had got my sister pic related (though that one is blue instead of black, so maybe it's not the same exact model as the one in the pic) that also takes a battery
plus the one i'm using myself, a logitech m650 L which isn't a flat one and takes a AA battery but that's because it's specifically made to not be flat, the battery really doesn't take up any space that would stop it from being flat. Like it could be half the height and the battery would still fit fine. Also, i think my dad also got a "mid size" (not flat but not too tall either) from i think trust, it's still pretty small and takes a normal battery too