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_27615520_1 (storage_medium VARCHAR, product_name VARCHAR)

### Question ###
List the number of ramsan-720 hard drives?

### Accurate SQL ###

SELECT COUNT(storage_medium) FROM table_27615520_1 WHERE product_name = "RamSan-720"