The trim kit is made of black metal that is manufactured to the highest quality.

that is a myth. there was no metal trim on their shoes. we just studied that in reading class today.

Metal is no longer used. Trim and moldings are plastic these days.

Valley trim is usually installed onto the roof preceding the actual roofing panels. If you are using standard panels with W-Valley trim (or similiar) the Valley trim is screwed directly into the lathe using "Quick-Drill" (metal-to-wood) screws.

You should get a metal one.