A nebelkerzenabwurfvorrichtung is a German term that means "smoke grenade launcher." It's a tool that shoots out a special type of grenade that makes a lot of smoke, like when you use a smoke bomb in a video game.
The people who use these launchers are usually soldiers or police officers. They use them to make it hard for the enemy or bad guys to see where they are or what they are doing.
Think of it like when you play hide-and-seek with your friends. If you use a smoke grenade, it's like a big cloud of smoke that makes it hard for your friends to see you, so you can run away and hide somewhere else.
Of course, in real life, it's a much more serious situation. The people who use nebelkerzenabwurfvorrichtung want to protect themselves and others from danger, and the smoke grenade launcher is one tool that can help them do that.