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_57 (sspec_number VARCHAR, i_o_bus VARCHAR)
### Question:
What's the sSpec number of the processor having an ultra-low power I/O?
### Answer:
SELECT sspec_number FROM table_name_57 WHERE i_o_bus = "ultra-low power"