What is this AT gun?

So I was watching a youtube video, and well... I came across this: WW2-Wermacht/Panzershrek Video - YouTube
So what is the name of the first AT gun? And if you know any information, if you could share it, thanks

 

I think it's either a
2.8cm Panzerbusche 41 taper-bore gun
or a
8.8cm Racketenwerfer 43 (Puppchen) that used the same carriage

The thick barrel makes me think the second but there was vey little smoke/backblast when it fired, still the "staged" look of the while affair makes me think it possibly wasn't a live rocket. I vote for Puppchen.

 

Oh, Thank you so much man! This has been bugging me for some time, it is the 8.8cm Racketenwerfer 43. I looked up some pics, and got this, which is strickingly simular to the one in the video. http://www.airlandseaweapons.com/img/upload/rrrgtf.jpg

Thanks agan