Welcome to the Q&A Forum

Hi moz fans!
I'm working on some client sites.
They have a lot of products, which they are selling through their webshop and two affiliate sites.
But I can't stop wondering:
The affilate sites are using the same product descriptions and images - Will Google see that as duplicate content?
And if so.. How can I prevent that? The two affiliate sites are well etablished and huge sites, so I guess they know what they are doing.. Is there some way I can check it? When I do a google search, whit the "My product description text", I'm getting some different results: Sometimes all three sites appear (main site, and affilate) Sometimes it's only the affilates Sometimes it's only the main site. So to make it short:
If i'm using affliate, will Google see it as duplicate content?
How do I check it, and how do I prevent it? Thank you!