[quote user="pickyh3d"]You could inherit from the class and add the Cardinality property.[/quote] the class is marked as not inheritable, i think that for performance reasons. The best way i have find is to use reflection to get the reference to the private backbone int32 array, and use this function that count byte to byte instead bit to bit. Private Shared _bitsSetArray256 As Byte () = {0, 1, 1, 2, 1, 2, 2, 3, _ 1, 2, 2, 3, 2, 3, 3, 4, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, _ 5