Blade SSD part numbers?

iMac 21.5 inch late 2013

Hi

I've just recently bought a new iMac EMC 2742 and planning on installing a 2.5" SSD together with a blade SSD.

Where the problem comes in is that i don't know the part number to the correct Blade SSD. I have searched Ebay and there are a lot of SSD's available but not always a clear answer to whether or not it will work in my computer.

Genuine Apple SSD's are expensive so i definitely don't want to order the incorrect part.

Thank you

Dominic