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_71290 ( "Device" real, "Device type" text, "Capacity [MB]" text, "Avg seek time [ms]" text, "Avg rotational delay [ms]" real, "Avg transfer rate [kB/s]" real )

### Question ###
What is the smallest transfer rate for a 3243 device?

### Accurate SQL ###

SELECT MIN("Avg transfer rate [kB/s]") FROM table_71290 WHERE "Device" = '3243'