--- What are different KFF fields?

SELECT kfc.segment_name
      ,kfc.segment_num
      ,kfc.application_column_name
      ,kfc.flex_value_set_id
      ,kff.application_table_name
      ,kff.id_flex_code flex_code
      ,kff.id_flex_name flex_name
  FROM fnd_id_flex_segments_vl kfc
      ,fnd_id_flexs kff
 WHERE kfc.id_flex_code = kff.id_flex_code AND application_table_name = 'MTL_SYSTEM_ITEMS_B'