some questions about bumper material

[amskater]

I just bought front and rear bumpers and my first question is how can you tell if the bumper is fiberglass or Polly-Urethane? These Bumpers are brand new they are a yellowish color. Would I have to sand them at all? Or should they be ready to Primer? I could use any advice anyone can give me thanks in advance

 

[cruisintalonawd]

Where did you buy them from and can you bend them farley easythen they are poly-urathane.

 

[Defiant]

Check the SPI code:
Plastic Recycling Code List

Didn't the seller know? WTF