This dataset provides eight feature classes. The base feature class is called CBSAa_cb and isn't generalized. The weighted centroids feature class is called CBSAa_cb_cent. The centroids are weighted by the U.S. Block Centroids population distribution. Use the weighted centroids in report aggregation and spatial overlay operations. The CBSAa_cb and CBSAa_cb_cent feature classes contain all the attributes. There are six generalized boundaries feature classes and called: CBSAa_cb_gen2, CBSAa_cb_gen3, CBSAa_cb_gen4, CBSAa_cb_gen5, CBSAa_cb_gen6 and CBSAa_cb_gen7. Use the generalized boundaries when creating study areas.