Exhaust help! 1978 super beetle fuel injected
 

I need to replace this piece. What's it called? I see it pictured in my repair book, but can't nail down the name to order it. Kinda new to this.
https://cimg0.ibsrv.net/gimg/volkswa...13a579eb09.jpg
What is the highlighted part called?
https://cimg1.ibsrv.net/gimg/volkswa...1400c06021.jpg