A pack of M8 x 1.25 pitch x 12mm Hex copper flashed slotted nuts for use with exhaust manifold studs. Whilst the copper flashing acts as anti-seize coating and helps to eliminate seizure on the manifold studs, the slotted section gives the nut anti-vibration properties and allows it to act as a self-locking nut. It's full metal construction makes it suitable for use on high temperature components.