Fiberglass Edging?

[Devilfish55]

Can someone name or describe the material used to cover the edge of the fiberglass? As circled in red in this photo.

 

[colbysmith]

Protective Edge Guard, Edge Channeling, Edge trim... probably other names as well.

 

[pcg]

https://tacomarine.com/trim-molding-flex-trim-v30-1005