Strut insert identification
 

I must be searching wrong, because this must've come up before. I have a set of front bilstein struts with a silver insert. There are no identifying marks that I could find on the insert. How do I know what type it is?

Strut part no is 911 341 041(042) 30. They came from a 78 sc.

Perhaps if I could spell... Sorry

TIA

What color are the strut housings? Bilstein are green or yellow - Konis are red, boge are black. Jim

The struts are bilstein greens, but the insert has no markings that I can see, trying to figure out if it's a sport or HD insert, any way to differentiate?