My husband discovered this week that his stethoscope also works well as a stud finder - he tapped on the wall and was easily able to discern where the studs were. But I'm guessing stud finder wouldn't be accepted. :)
Nope, Karabiner is the Mauser rifle the Germans used in World War 2, a shortened version (carbine) of the rifle they used in WW1. Many other countries in Europe and around the world used it and almost all modern bolt action rifles, that is hunting guns, are based directly on it.
The brass knuckles were like an optical illusion to me. I could only see the wood as an object, the rest was empty space. Not until I saw the answer did the brass knuckles suddenly appear!
I think it's kind of funny that the Pommel Horse is one of the least known objects. I guess not many people are fans of men's gymnastics, I mean, I'm more of a women's gymnastics fan, (since I am one) but I still know all of the men's apparatuses.
But it is also the name of the item in the picture
https://www.thebmc.co.uk/karabiners-and-connectors-for-climbers
Also, 'round my parts we've always called megaphones "blowhorns".