The XPS-DR power supply comes as standard with a black S-XPS Burndy cable. As others have mentioned the 555PS does not come with a Burndy cable as it’s assumed that if you’re connecting an NDS or ND555 then you would use the dual Burndy cables that come supplied with those sources.
If you want to use a single connection from 555PS to NDX2, nDAC, CDX2 etc then the black S-XPS Burndy cable is the one that you would need to buy.