I found this on eBay. Help if it it's authentic or not please!

So I really want a silver Nexus 6p and I found that eBay sells the back covers and then the fingerprint sensor separate. Does anyone know if these are OEM parts or are they aftermarket. They all seem to be the exact same and run roughly between 15 to 20 bucks the the silver fingerprint sensor runs about 10 bucks so around 30 dollars I can turn my frost white into the silver model I would rather have. Does anyone know if these parts are original or are they aftermarket? Any help and advice is greatly appreciated!! Thank you.