No.  The hub style combination used is based on the size of the coupling and the bore sizes required.  Some ServoClass sizes have a reduced diameter hub for smaller bores that provides a higher clamping force to achieve optimal performance. Not all ServoClass Coupling sizes have a reduced diameter hub.  The ServoClass Coupling sizes that have the reduced diameter hub are listed in the catalog, along with the range of bores that use this hub.  Bore sizes larger than the maximum bore of the reduced diameter hub will utilize the standard diameter hub.
Style "A" has (2) reduced diameter hubs
Style "B" has (1) reduced diameter hub & (1) standard diameter hub
Style "C" has (2) standard diameter hubs