Unfortunately that doesn't mean anything. You might just as well have written it in Chinese. What you need is a box to house an item of unknown (to us) size. It might help to mention the size.
I keep mine in one of these under-seat toolbags. There are all sorts of sizes and shapes. The advantage is that you can stick all the over-length cable in there too. My controller has lived happily in that bag for 10 years. I also have a compartment for a puncture kit in mine.
The controller is rated at 7 amps but will carry a maximum of 15 Amps which is common enough for 250W rated motors.
That's it. The rated current doesn't mean much. The controller is guaranteed to run at that current all day, but the actual current you use is rarely at the maximum unless you do something daft, like use it for a 328 rpm motor in a large wheel, which will overheat it. Please don't ask how I know.
