Extra long life iridium plug, 12 millimeter thread size, 26.5 millimeter (1.04 inch) reach, 5/8 inch (16 millimeter) Hex size, gasket seat, resistor, extended reach, stainless steel gasket, solid terminal nut, 0.7 millimeter fine wire iridium-tipped center electrode, 044 inch (1.1 millimeter) gap, heat range: 22.