Accessory rail screw

I make a direct attach light mount the other day for my vector. I have one set of screws that came with a midwest industries MLOK adapter, but I need another set so I can make a plate to put my pressure switch on the left side of the gun. Does anybody know what the size of the screw is? I will post a pic shortly of the light mount. I just need to spray paint it and get it mounted correctly.