What is this pipe behind the engine going into heat shield?

[Duke48]

An evil animal has destroyed my heatshield behind the engine. I am getting a new one with all the bolts needed, however I'm no sure if should I ask mechanic to change it or not. I see only one thing that needs to be disconnected.
What is the pipe marked red on the picture? I need to disconnect it in order to replace the heat shield.

https://i.postimg.cc/GhHLq27G/1.png

[fastboatster]

this a vacuum line for the brake booster