Front driver Exhaust Manifold Shield bolt/nut size?

[dclark2171]

This thing rattles super loud. The passenger side does not have one. What size nut/bolt can I go get at a hardware store to tighten this thing back up?

 

[dclark2171]

I wire tied it, and it's as silent as a mouse now. Next time I take it in, I'll have them properly bolt it together. I'll be curious how long the plastic tie lasts before it melts