This is the XCS version of the SD 8 Pin Lemo Center Post cable for PRO posts (or XCS posts with PRO mounts). As described on the XCS web site: FGG 3B 308 connectors on both ends. Yellow 308 coiled cable uses 16 AWG conductors.
This cables is a slightly tighter fit in a 1.5" post but does fit and because of the larger diameter cabling you don't get voltage loss (or much less of it). Pro no longer sells an SD cable and XCS charges $650 for it.
$350 plus shipping.