I wanted to replace my C5 (Year 2007 2.0L Petrol) driveshaft inner gaiter (The rubber cover). So I sent the picture of the worn rubber joint as attached to the dealer:



But the dealer given me something that is too small to fit:

The dealer assured me that this rubber cover is certainly meant for my model. Unless, I'm able to tell them the exact part number, they are unable to allow an exchange.
Can any kind souls here advise me what should be the correct part number of these rubber cover?
Thank you very much.
Regards,