EN 50216-4 specifies basic accessories of transformers / reactors, such as− Thermometer pockets, to be used for liquid immersed transformers,− Earth terminals; to be used for liquid immersed and dry-type transformers,− Draining plugs, to be used for liquid immersed distribution transformers,− Filling openings, to be used for liquid immersed distribution transformers,− Rollers, choice and distance to be used for liquid immersed and dry-type transformers.After agreement between purchaser and manufacturer, this part of EN 50216 Series may still be applicable either as a whole or in part to large power transformers or special transformers.