Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
What manufacturer has a wheel arrangement of 4-6-6-4, and a Class of z-7?

### Inputs:
table_name: table, columns: ['Class', 'Wheel arrangement', 'Fleet number(s)', 'Manufacturer', 'Serial numbers', 'Year made', 'Quantity made', 'Quantity preserved']

### Response:
SELECT Manufacturer FROM table WHERE Wheel arrangement = 4-6-6-4 AND Class = z-7