Some of the user comments for the DX SSC P7 seem to suggest that the voltage bin is I-bin (3.25V-3.50V), even though the ad implies J-bin (3.50V to 3.75V). Either way, these small voltage differences vs. an MC-E (in 4P) probably don't matter.
The driver is claimed to be constant current. The ad copy also says:
-Be compatible to CREE/N2---P4---Q5---R2---R4---MC-E;SSC/P4—P7;