If the runflat system was not chosen, the wheels came with beadlocks installed. The beadlock spacer looks just like a one piece runflat with no tread support section. It is smooth on the top. Since the tire just slides over the rim when assembling, the bead seat area is not very deep and may not retain the bead like a normal 1 piece rim will. Supposedly the new 1 piece design has a higher load capacity, improved looks, and reduced weight.
First lets consider beadlocks.
The bead lock spacer is a short plastic rim, similar to the old beadlock spacer. However, it is cut into two semicircular halves. Hence, each half is inserted into the tire and then bolted together. The other tire bead is then stretched over. It is real pain to install.