Help with bolt size in engine bay on support rod

[daelo]

As you can see by the picture below...(just below the green wires) there is a bolt missing from this silver rod that comes off around the alternator and then attaches to the engine block.

Would like to bolt this back together to secure everything back up!




Thankings in advance.. probably get this from renault if someone can help me with the size of it...or get a similar 'M' bolt and then file down to the correct size.