Frontpipe to manifold and Middle section to catalyst nut. This is M12 x 1.25mm with a 17mm Hex which is quite rare. This size hex allows you to use a normal socket on the front pipe to manifold studs making fitting the frontpipe a whole lot easier. A lot of aftermarket suppliers supply normal nuts which are not designed for the high temperatures encountered. Price is for ONE Mitsubishi Part Number MB059359
