Sorry for the delay, the catalogue says (I am selling with brand new C-Bear Shimano adaptor ) :
An example of this is the BB30A found on found on bikes like the Synapse, EVO and
CAAD12. The “A” stands for Asymmetric - the BB30A adds 5mm to the non-drive
side of the BB shell for a wider, stiffer base. To accomodate the wider BB shell, the
BB30A gets a longer spindle and the non-drive side crankarm angle is changed to
maintain the same Q factor and even out ankle clearance on both sides. Cannondale
HollowGram BB30A cranks will work on both BB30 (68mm BB width) and BB30A
(73mm BB width) by changing the non-drive side spacers.