A process for making a poly alpha-olefin (PAO) having a relatively high vinylidene content (or combined vinylidene and tri-substituted vinylene content) and a relatively low vinyl and/or di-substituted vinylene content, as well as a relatively low molecular weight. The process includes: contacting a feed containing a C2-C32 alpha-olefin with a catalyst system comprising activator and a bis-cyclopentadienyl metallocene compound, typically a cyclopentadienyl-benzindenyl group 4 transition metal compound.