Top Law Schools

Does anyone know the difference between LL4056A and LL4056B?

Also, can anyone compare the Kaplan Mastery content/components to Cambridge by type and equivalent? For example, does the Kaplan include RC by type?

LL4056A = Kaplan Mastery 2006
LL4056B = Kaplan Mastery 2007
(This is just based on info from Amazon.)

Kaplan includes RC by type. It also includes Kaplan's explanations for all questions contained, while Cambridge does not include explanations.