Iridium Max T. he NGK IRIDIUM MAX are the improved and reinforced version of the Iridium IX. These series combine an Iridium center electrode of 0.6mm diameter to an implant of platinum on the ground electrode. Compared to conventional ground electrodes, the platinum improves the conductivity while significantly reducing the electrode wear. These series also feature a brass head module with very low impedance (Ohm) as the same way as Iridium Racing series (IRI-Series NGK). Fine Iridium tip guarantees high long service life and consistent stable spark. Has extremely high melting point. Longer life than Iridium IX Spark Plug but with the same performance. Maintains longer performance than Platinum Plugs. *By request/order.