Samsung S8+ What are these 4 white plastic bumpers for, 2 on top, 2 on bottom.

[Perryinjax]

On the top and bottom edges of my Galaxy S8 plus, there are small white plastic lines. 2 , on top and 2 on bottom.
What are they? Are they bumpers?

 

[Tim1954]

A continuous metal loop can act as an antenna. They put plastic bits to break up the continuity to avoid this.