Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_9 ( apparatus VARCHAR, rank_final VARCHAR, competition_description VARCHAR )

### Question ###
What is Apparatus, when Rank-Final is greater than 6, and when Competition Description is 'U.S. Championships'?

### Accurate SQL ###

SELECT apparatus FROM table_name_9 WHERE rank_final > 6 AND competition_description = "u.s. championships"