Germans are at it again

I don't know what Germans have to do with it, but I do know what Vine has to do with it:
,
https://youtu.be/2Bjy5YQ5xPc

Thänks:)

He's yeeting his grenade

The end part isn’t his arm

That's the grenade, they had long handle-like extensions on them back then, not like the small compact pull the pin and shove it down someone's pants things we have now.