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_33 (prr_class VARCHAR, wheel_arrangement VARCHAR)

### Question ###
What PRR class has a Wheel arrangement of a1a-a1a?

### Accurate SQL ###

SELECT prr_class FROM table_name_33 WHERE wheel_arrangement = "a1a-a1a"