All 1U Rackmount Chassis will come with a single slot PCI Risercard.
This will have either a single 32 bit or single 64 bit slot.
All of our 2U Rackmount Chassis will come with either a 3 slot 32 bit or 2 slot 64 bit Risercard, dependant on the model.
There are alternatives however and when you look at the details of any of our 1U or 2U Rackmount Chassis you will see the different types that are suitable for each particular model.
Rackmount Chassis of 3U and above do not need Risercards.