Closing the display of an open iPhone 11 - do I need to purchase the seal?

[benyben123]

New to iPhone 11.
Phone was dropped.
Opened it up for fixing.
Managed to fix it (here: https://forums.macrumors.com/threads/iphone-11-wont-recognize-sim-after-drop-pics.2310194/)


Question: do I need to buy a new adhesive/seal (see pic)? Or are these optional (I don't care about it being waterproof!)?


Thank you!

 

[BugeyeSTI]

The seal is for dust and water resistance, I would replace it unless that's not important to you.