text: Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
  ### Context:
  CREATE TABLE table_name_56 (thickness VARCHAR, diameter VARCHAR)
  ### Question:
  Which Thickness has a Diameter of 21.9mm?
  ### Answer:
  SELECT thickness FROM table_name_56 WHERE diameter = "21.9mm"